How do I fix a bike lock?

I accidentally jammed my OnGuard U-shaped bike lock. There are two parts to the lock: a metal “U” and a straight part that contains the combo and snaps into the U.

There are two ends to the U. One is straight and the other is slightly curved. You are supposed to put the curved end in first, but I somehow jammed the straight end in first. Now, I can’t attach the curved end or unattach the straight end.

Any suggestions?

http://www.amazon.com/OnGuard-Brute-5001-Bike-U-Lock/dp/B000FL4Y3S