The one on my nearside is not square either. You should be able to adjust the hinges to allow for this, assuming the bolts will move ! Or you can try bending it back carefully with a large adjustable spanner, g-clamp, or other suitable tool.
Alternatively try giving it a good wack! - It worked for me after a minor parking mishap - a bit of heat on it might help as well! Take the bonnet off for better access. Its not an issue as you'll need to re-align it anyway. Good luck as its a b*tch of a job to do!
I did post this in one of your other threads on this subject, but I'm not sure that you saw it. Use a G-clamp on the corners and squeeze it back into shape, a bit of heat from a small blow lamp should help a bit too.