I'd use 25 - 30lbs, as they are nylocs, they need only be very tight as the nylon ring should stop them unscrewing.
You will need a taper joint splitter, and if i remember from one I did, the joint is placed in such a way that it was a nuisance to get the splitter in position. Otherwise as normal I guess.
If you put the car on stands using the jacking points, then you must make sure that the spring does not push the lower wishbone away by using a spring compressor to hold the spring stable. Another way is to support the lower wishbone on a trolley jack of course. I prefer a compressor though!