Use a flat screwdriver to push it back in... but the crack isn't easy to deal with.  If it's not broke at the nose (where it's bent the most)  you could use a rail cover to hold it in place, and cover the crack.  (like the one at the rear)
The one on my old sportster was broke, and I found a new one on ebay.  BUT... they aren't common. (or cheap)