here's a few ways I've dealt with the top two bolts on my manual trans.
-Large open end wrench from the top: Can't get a good position, slips, bruised hand, curse.
-slip a pipe over the open end for leverage: see above.
-use a cheap u-joint socket adapter from underneath: slips, bruised hand, curse.
-use a good u-joint socket adapter: fewer bruises, same amount of cursing
-remove the crossmember, lower the trans so I can reach from underneath: curse when the distributor hits the firewall
-remove crossmember AND distributor: can now reach the bolts with a standard socket extension and BFTorquewrench. Curse just because I'm used to it now.
-Easiest solution- don't replace them, so the next time you do this, you don't have to worry about them!! (they're just there for show anyway, right?)
As bad as it was, it still wouldn't warrant taking out the engine. And I'd give my Brother-in-Law's right arm to have a car lift for the job!