Hi,
can you post a picture of one of the speakers please ? I have not seen a set of these as yet, and I am concidering changing mine out to some decent ones.
When you say that one of the speakers is distorting, do you mean that it rasps/ farts continually or is it just that some tacks come out as very unclean? if it is the later then I don't think that your new set is going to help. my speakers do the same and I find that the only way to solve it is to turn the stero down. when I had my headunit in my MR2 running Focal 165s I could turn it up to about 26 without distortion. In the SL with stock speakers I get 17 at the vary max
Now to the list of screws
This list is by way of the drivers corner

it bears little resemblance to our model. But I think that our door will be a small sub set of these. From what I can see MB simplified alot of the door stuff...
+++++
Door Panel Removal
1. Remove the small piece of wood trim above your seat controls.
2. Remove the phillips head screw behind that piece and pull off that
metal piece it was holding that is hooked at the end by the door lock
switch.
3. Pull out the door lock switch
4. Pop out the seat switch piece of wood and disconnect the harness
5. Open your map pocket. You will see a small piece of plastic toward
the front with a small screw, remove that and the piece of plastic.
6. Remove the screw recessed deeply in the hole in the rear section of
same map pocket
7. Remove 3 screws holding the chrome plate on the rear top of the door
8. Pop out the door light and disconnect it (2 wire black plug)
9. Take a 10mm socket and remove the bolt from behind that first piece
of wood you removed.
10. Get a BIG phillips head screwdriver and remove the large screw
behind the little piece of plastic that was in the map pocket
11. Remove the triangular piece of trim parallel to the side rear view
mirror (pop the top section and pull up)
12. Pop the snap connectors along the bottom edge of the door panel.
13. Reach under and disconnect the yellow vacuum line for the door map
pocket lock
14. Lift the entire door panel up to remove
The Drivers Corner