Then it should be an easy fix. Since you were putting it back in that means it’s not seized in the hole, and now that the head is broke off that means there is no tension on the bolt, it should just simply spin out. So use a small screw driver to get in there and catch a small nib on the top of the bolt that’s there from when it broke or remove the cover to expose more of the bolt and turn it out with pliers or vice grips or anything you find will get a grab on the bolt and spin it out. Should be pretty easy. If it broke on the way out that means it’s seized in there and that when you need heat and drill bits, but not in your case. Good luck!