Re: Another leaning garage
It's hard to tell how much the walls are "off the slab". A little bit, completely off, etc. Also hard to know what caused them to move off the slab. If you hire someone to fix it, they'll probably use some form of a jack to raise the roof from the inside, to take the weight off the wall.
Once that's done, something as simple as using a sledge hammer and knocking the floor plate of the wall back over the slab could be accomplished with not too much effort.
The bottom line is that what you're describing can be done. The specifics of the situation will need examination before a complete solution can be described here.