Tuning FX Tarantula trigger lock

Never heard of trigger locking due to too high pressure. Do you mean valve lock? That happens when the pressure is higher than what the hammer can strike at the valve. So you get little to no air release when the hammer hits the valve.

Some guns will have a bleed screw to bleed off the pressure. Most guns don't have it. You can try hooking your handpump or tank to your gun and fill it. When the pressure gets higher than what's inside the gun, the one way valve will open. Slowly bleed off the handpump or tank. It will release the air inside the gun. If it doesn't, that means you open it too fast and the one way valve lock back up. Repeat and slowly open the bleed. It will bleed off the pressure inside the gun without closing the one way valve.