Flat ground (versus a slope) would be better. Can you do it in the 1 car garage?
Have done a few engine removals/installs in 40s, it doesn't take a bunch of room. I swapped the engine/tranny in a single bay of my garage. A bunch of room is nice because you can spread out parts, but carefully organized all the parts you need to remove for an engine swap will fit in the bed of an FJ40 just fine.
Ricardo Maestas - Bio Page
1999 LX 470, 1971 FJ-40