There are a few ways to get a stuck choke tube out. The first is to try using a black powder gun cleaning rod. Simply insert the rod into the muzzle of the gun and tap it with a mallet until the choke tube pops out. If this doesn’t work, you can also try using an air compressor. Put the air compressor hose on one end of the chamber and blow into the other end until the pressure builds up enough to dislodge the stuck choke tube.
Finally, if all else fails, you can always take your gun to a qualified gunsmith who will be able to remove the choke tube for you.