I am trying to install a prehung door into a frame that is not square. The door I removed always shut by itself and after removing everything I now see why. There is not enough room to use shims to adjust for this. I know because I tried, I leveled the top, squared the hinge side and the door does sit fine but I don't have enough room to move the latch side jam over for the door to shut. In order to have the hinge side level I put the top of the jam tight against the frame and there is about a 1" gap at the bottom. What are my options besides tearing out the wall? Any help is greatly appreciated.