The only trick in reinstalling the guides is the blind nuts behind the window for the upper guide. They’re loose and nothing holds them in place. I had one fall out, though managed to thread the other one first try, got lucky. To reinstall the nut and try again after it fell out, I inserted some string through the bolt hole front-to-back, placed the nut on the far end of the string, and knotted the string so it wouldn’t come out through the hole... then simply drew it back up into position.