Is it the main mast of the plastic block that attaches to the Jeep?
If it's the mast, that just screws into the plastic block. If it's teh block then that screws into the side of the Jeep. You could be able to feel the screws up under the dash. I think they're just sheet metal screws and not bolts though. If it's loose then you might have to swap to bolts or else use larger dia screws.