You don't have to release any pressure from your gun.Just remove the receiver cover and loosen the small Phillips screw which will allow you to slide the adjustment ramp.Insert the preferred pellet as a guide, you may have to slightly manipulate the cocking handle lever just enough to allow the plate on the adjustment ramp to move.Once the pellet is inserted, position the pellet skirt flush with the opening in the plate and tighten the Phillips screw.You should now have the proper clearance to use for your preferred size pellet.