The Hi-Tie is double bolted to an interior rib of the trailer. I simply pull a pin to swing the arm out and then put the pin back in to keep it in the open position. I just do the opposite to put the arm back in the traveling position.
The Hi-Tie arm is made of some specialized, flexible, hi-tech fiberglass material. It gives, but doesn't break if a horse pulls back or puts pressure on it. For additional security, I snap a Blocker Tie Ring, my second favorite gizmo of all time, to the top where Speedy G's rope is attached. If he pulls back (it's happened), the rope slips through and he can "free" himself. And since he's already standing away from the trailer, he's less likely to whack anything.
Because he has so much room, Speedy G likes to lie down at night if we're camping with the Hi-Tie, and if he thinks he has enough room, he also rolls. Unfortunately, he's not the best judge of "enough room!"
Of course I bought the Hi-Tie for endurance rides, but it has been very useful at dressage shows, too. After my tests have been completed, I swing out the Hi-Tie and Speedy G can hang out at the trailer pretty comfortably while I watch others ride. With his hay bag, feed pan, and water bucket nearby, he's pretty happy to just stand around and watch the activity. He does like for me to check in on him occasionally, and if I stay away for too long, he'll give me a holler!