Get yourself a 3'-4' pipe that will fit over the peg. Slip the pipe onto the peg and lift up. Once it's moving upward you can continue to bend it up by striking it with a hammer. It may bend far enough that you can twist it out. If it doesn't get that far, cut off what you can with a hacksaw and leave the rest.
Removing that much bark and opening up the vascular system will open a huge wound with huge risk. So don't start cutting on the tree. The tree will grow over whatever remains and heal itself.
That is inexcusable. I wouldn't let those hunters back on my land. No respect for you or your trees.