In too deep: illegal technique

Somehow I convinced my college to fund a 23k piece model of campus! Very exciting, but the stress is on. I made the model in bricklink and they didn't flag the illegal technique pictured, so I ended up using it somewhat frequently. I learned recently it's illegal to do that (thanks to the Model T "scandal"), and lo and behold, when I try that connection myself irl it's pretty difficult to stick on. I can tell the bricks are stressed. An easy fix would be to change the model. But the pieces...