I started off doing easy stuff like oil & filter changes , brake shoes and so forth . Exhaust systems were also easy diy jobs .
The first biggish job was a clutch replacement on my Ponton back in the early 80's : the design of the Ponton series was such that the engine , gearbox and front suspension were all mounted on the fahrenschemel ( subframe ) which could easily be dropped out as a unit , and that was how I did it . Whilst doing the clutch , I also ordered a new starter ring gear and took my flywheel in to Western Mercedes in Edinburgh who kindly heated the new one up and shrink fitted it on for me , at no charge - they told me to bring it in and offered to do it , I didn't ask .
Since then I've done all sorts myself - engine and gearbox swaps , coil springs , suspension rebuilds , brakes ... I did a cylinder head gasket on an Audi years ago , did a clutch in a Polo , water pumps both on the Ponton and on a 190E , replaced the Webasto sunroof on my Ponton , have changed ( non bonded ) windscreens and door window glasses , changed interiors ; upgraded one of my W126's from manual cloth interior to electric , heated , leather interior , after which no one would have known it wasn't factory since I tok everything out of the donor car very carefully and fitted it exactly the same into the other one . Also upgraded one of my 190's to orthopaedic seats , after finding them in a breaker . I've also fitted towbars to most of my cars , usually sourcing them from breakers or from eBay .
My current 190E is a good example : after getting it a few years back I ran it for a year and noticed the signs of head gasket failure , turned out the head was corroded and would need repaired . Since the 1.8L engine was underpowered I decided to look for a 2.3L engine as an upgrade , and bought a known good unit from a fellow member on this very forum for the same sort of money as I'd have spent repairing the old engine . I then went and bought an engine crane to do the swap ( previously used a block and tackle off the steel beam in my dad's garage when he was still around and I was younger ) , it is a handy thing to have . The 'new' engine came with gearbox attached , so rather than split them I just swapped the two lumps over . I had to cobble a few electrical connections since the W201 and W124 wiring differed slightly , but it was not that difficult . Along with the engine upgrade , I upgraded the front brakes to the same spec as the factory 2.3L 190's , with larger , vented front discs from a W124 260E , bought the tool for flaring the ends of brake lines and made up new pipes throughout and fitted new flexible hoses . I previously used to buy ready made brake pipes from the dealers , but these have shot up hugely in price and are no longer cheap ; much easier to buy a roll of Kunifer pipe and unions and make them up as I go . Also bought a vacuum bleeding unit which works off my compressor and makes bleeding and fluid changes easy .
I've had a decent sized compressor for a while and , besides just using it for tyre inflation , also use it for running air tools which are very handy . At some point I'll try my hand at painting , but will start off with easy things like wheels or scrap panels before doing my cars . I have two genuine front wings and rear wheel arch repair sections for the 190 and these will go on sometime soon-ish . I bought a MIG welder a few years back and have made up frames and things but not yet done any serious welding on my cars ( I bought it with the intention of restoring my Fintail , which needed a lot of welding , but that car turned out to be made more out of rust than anything else , so the project was abandoned - only time I've ever done that and failed to get a car on the road - it was bad ) .
Currently the 190 is up on ramps at the front and axle stands at the back with the diff ( which started making a nasty noise ) out . The original diff which went with the 1.8L engine is too short for the car now and I've bought the taller diff from a 190E 2.6 to do in . I discovered the driveshaft flanges are a different size and now just waiting on a friend bringing me a complete rear subframe from a 190E 2.5D which has the same shafts . I'll swap my 2.6 diff into it and clean it up before fitting , and look at doing the subframe mounts when I'm there . Also just bought a rear exhaust section as the old one was rotten and I cut it off while removing the old diff .
Further ahead , I have a fuel tank swap to do in my R129 - I have the new tank in my shed , but I need the 190 finished first , hopefully over the next few weeks . The SL will also need a little bit of welding to the well under the battery tray - I suspect that water has been gathering there somehow as it is hidden and rotted it out , the opposite side well is fine as the drain hole is clear , and there is no other rust - should be an easy little repair and within my abilities . The soft top is now pretty tatty and I'll replace that at some point , having previously stitched the window panels back in , and I need to replace the leather on both front seats - these again are jobs I'm happy to do myself using good secondhand parts .
Over the years , I've assembled a reasonable collection of tools , all the basic hand tools , spanners , sockets , a couple of torque wrenches , several specialist tools for particular jobs , spring compressors , Pela oil extraction tool , compressor with air ratchet and gun , air cutting tool , nibblers , spray guns ... MIG welder , ramps , axle stands , trolley jack and no doubt more that I can't think of right now .
I would suggest starting off with the easy stuff first - basic service items like oils , filters , brake pads - then move on to more advanced jobs as your confidence builds . If there's a Haynes , or other , workshop manual for your car , that can be a help - also remember that YouTube can be a great resource with lots of people filming 'how to' videos and putting them up - there's a guy Kent something in USA who has a site mercedessource who has a lot of very good videos showing how to do jobs on many of our cars .
To begin with you could do worse than get one of the Halfords Professional toolkits , these go on offer a few times a year at half or less of the usual price , and they will also have things like trolley jacks , ramps or axle stands - Halfords can be pricey for some things , but OK for others , and very handy as they are everywhere . Machine Mart and Costco are also useful places for tools , but do shop around and compare .
Most of my hand tools came from Halfords Professional or Advanced ranges and are pretty decent without being Snap On expensive - I do a fair amount of diy and they serve me well . My compressor came from Costco and my MIG from Machine Mart . I also have a machine polisher which came from Machine Mart , as did my engine crane and trolley jack . The crane came in a couple of boxes which fitted in the boot of the R129 , so not hard to get home .
I've worked on older British cars : Minis , Triumph Heralds , Hillman Minx ; VAG , from air-cooled Beetles , through Mk 1,2&3 Polos/Derbys , Golfs , Passats , Audi 80's and 100's , then my various Mercs from the 50's , 60's , 70's , 80's , 90's , and the money pit S203 which wasn't so DIY friendly . I've also had the misfortune to work on some French cars , which I hate with a vengeance .
Do see my sticky thread at the top of this forum 'Safe Use of Jacks' and bear in mind safety first when doing anything at all under the car . Also be safety minded when working around electrics or fuel systems and read up on safety precautions . Basic things like nitrile gloves to protect your skin from fluids , eye protection if working around fluids under pressure or if cutting , grinding or drilling , and , of course , welding - but again read the safety advice before starting on any new activities .
