I have a 1986 190e 2.3 8v 325,000km (~203,000mi) and want to replace the engine with one from a complete, running 1986 300e (105,000mi) parts car. I have almost no experience with auto mechanics and am doing this project mainly because I want to learn how to do this stuff. The 300e is listed as parts only, so it can't go back on the road. The 190e is currently not being driven because of mechanical issues (hence the engine swap).
I have removed the engine and transmission from the 300e and it is currently on a hoist.
My questions are
(1)What do I need to do mechanically to make it work?
(2)What do I need to do with the wiring/electrical system to make it work?
(3)What problems/possible setbacks/additional costs should I expect?
I know these questions are very broad, but I have to start somewhere!

Dan