It is a direct swap if RWD to RWD. I ran E90 BMWPS on my E82 (I wanted the higher spring rates). It was plug and play. Also, verts get a thicker rear spring (heavier car), so swapping to a non-vert might cause the rear to sit a bit higher.
Rent spring compressors from autozone or something. You can use a 3/8" socket adapter to spread the knuckle... Use two actually. 1 at the top and 1 at the bottom. Jam the square in and then twist it until it is wedged by its corners.
Thanks for the reply. Yeah I know the front spring are changeable from the e90 to the e82 of both are 6MT/RWD, but just to make sure are the struts changeable? Trying to swap out my ohlins so they can get rebuilt