Normally an insert made of aluminum or steel doesn't screw into the head, only glue. Apply some heat to the point and pull the insert out if you can.
Like James said , if epoxy and not hot melt , it takes more heat. Screw into an old arrow to make it easier and use the pliers to grip the broadhead (safer than fingers).
Sometimes a Bic lighter will do it, other times a propane torch is handy.