i do mine with car ramps. wear crappy old cloths, a hat, some sun or safety glasses and start spraying the bottom first. i slide under and hit the back side of the tranny, the rack, then in the middle of the tranny and engine, up the side of the block too, then the oil pan and front of the engine block. from the pass side wheel well you can shoot cleaner on to the tranny, and hose it off from there.
then spray the top 1/2 of the engine and tranny down. get 2 cans, one is never enough.
if you see any thick areas of built up grease use a old paint brush to break it up.