How do you fix a stapler that bends the staple crooked?

When you say it bends crooked do you mean it goes -almost- flat? well if so, the silver plate that moulds the stapler has most likely been turned around. press it down and it should pop out and just switch it to the right way.

OR

buy a new stapler :p

the problem is that the top end becomes misaligned with the crimping plate and the staple does not hit the curve, but instead hits the top of the plate. I just fixed mine. There are two guides either side of the staple tray on the base. I put a piece if alum flashing over one of them to hold the head in the proper position and glued it so that the barrel was pushed back where it is suppose to be.

Or u can buy a new one.