Apex3D AGM battery extender instillation instructions.
Remove the screws in the battery door using the provided screwdriver or another #00 cross tip. If it doesn't bite properly or feels like it's going to slip you may need to file down the tip of the screwdriver to make it have better contact. Remove the battery door.
Replace the battery door with the Apex3D extender. Install the blue screw, don't tighten it down. Next install 2 of the provided nylon screws. The nylon screws are used to prevent damage to the scope due to improper installation and cross threading. Tighten the Nylon screws down just until they're snug. Do not over-tighten them and strip them out. Next tighten the blue screw down until it's snug. do not over-tighten.
Using the screws that you removed with the battery door, Install the battery door onto the extender. Tighten the screws down but don't over-tighten them.
Install the batteries and enjoy your hunt.