If he is afraid of being tied (trapped) if you have a small pen, teach him to stand while at liberty. Let him wear off his sillies first if he's so inclined. Teach him to stand while you walk around him with one hand touching him. If he doesn't move, pop a treat in his mouth. (incentive) Do this a dozen times and he'll want to keep his feet glued to the ground. Only then do you gradually increase the size of your circles as large as you can. Because he feels he can escape an unseen predator the horse is often quite willing to stand and it's out in the open. Barns are claustrophobic to horses. Mine will stand all day if I just throw the rope over their back or neck. If he's rearing while you lead him, put a stud chain over his nose so it crosses over the noseband on the halter (not a knotted halter) and as soon as he goes up, give him more lead then suddenly pull him sideways. This will pull him off balance and usually scares the wits out of them.