Place the Bauer helmet on a table and use the screwdriver or drill to remove the screws. Unscrew each section of the facial cage from the helmet. Place the screws together in a safe place so you do not lose them.
Remove the old cage from the Bauer helmet and discard. Take the new cage and align it with the holes on the helmet. Make sure they are even and match up--you do not want the wrong-size cage on the helmet.
Put the screws back into the holes and turn until they are tightened. Have the player place the Bauer helmet on his head and try to move the cage. There should be no movement of the cage, and the player's view should not be obstructed. Double-check each screw to make sure there are no rough edges sticking out and that they are flush with the helmet.