How to Remove 3400 engine and trans through bottom?

I'm replacing the engine and transmission in my 2002 Alero 4dr and was leaning towards removing it through the bottom and wanted a rundown on what all i have to do before i jump in :crying:. The engine and transmission i am putting in is complete and from a 2004 2dr. I have had the subframe partially dropped a year ago while replacing the rack and pinion. Any info would be great.