make sure you dont put to much pressure through it.
Probably best to do this without the air bottle attached to start with.
Turn the gun upside down.
With the barrel facing away from you and the ASA towards you, turn the nut at the top of the front reg anti-clockwise till it stops. The nut should go further into the handle if your doing it right.
Once it stops, no air will be able to get through the system.
Attach the air bottle and start turning the nut at the to of the front reg clockwise while firing the gun (make sure the eyes on the gun are switched off)
The marker should start to fire after a few turns.
Keep an eye on the pressure guage on the grip frame, make sure it doesnt go over 200psi.
I think the recommended psi is 160. but can be adjusted later.