Things You'll Need
Instructions
Open the gun's grip. Unplug the battery. Use a screwdriver to remove the screws connecting the grip to the body of the gun. There should be two screws.
Remove the barrel of the gun by twisting it counter-clockwise. Set it aside. Remove the screw just above where the barrel was attached to the body of the gun.
Pull down gently on the grip. You will see a blue tube. Remove the tube and its fittings from the gun using an allen wrench. Set the grip, tube and fittings aside. Pull the metal frame from the plastic body of the gun. This will cause a small circuit board, the vision eye board, to pop out. Locate the wires running from the primary board to the eye board. Unhook these wires and remove the smaller board.
Remove the main board as far as possible. There should be three hoses still connecting the board. Use the allen wrench to remove the hoses, and reconnect them in their corresponding place on the new board. They are different sizes, so each will only fit in one spot.
Slide the new vision eye board into place, and connect it to the plug on the main board. Slide the new primary board into place.
Reattach the blue hose using its fittings and the allen wrench. Pull the battery wire from the new board through into the battery compartment. Replace the three screws you removed, and the battery.