Force lower unit

Does anyone know how to put a force lower unit back together?
I took mine apart to replace the water pump and curiosity got the best
of me, I decided to inspect the gears as well. Next thing I know
theres parts all over my garage consisting of gears, bolts and little
piles of needle bearings here and there, those suckers are small but i
think i was able to retain most of them. Also, if you know of a good
welding shop that deals with aluminum, that'd be great too. As I pryed
the lower unit from the mid section of the case a small chunk of
aluminum was broken from the casting. I tried a coat hanger and a blow
torch to weld up the small hole left by my crowbar, but that didnt
work and now theres a large fist sized opening. JB weld supported by a
mesh of screen (provided by my screen door) doesn't seem to hold too
well, as the epoxy keeps dripping out, once again exposing my
mechanical shortcoming. I'd like a reply fairly quick if possible, I
plan on taking the boat out this weekend.

TIA!

OH, P.S. Charles, we can try yours next weekend, if you want to..