How to change batteries in your garage door opener, remote and keypad
How to change the battery in your visor or keychain remote control:
You will need a replacement 3V battery and a small screwdriver. To replace the battery, open the case: there is a slide on the side of the remote. Insert a screw driver tip in it and slightly twist it, it will remove the top of the case. Remove the old battery and replace it with a new one, placing it positive side up. Snap the case back together and make sure to dispose the old battery properly. After changing your battery, you will probably need to re-program your remote control.
Garage Door Remote Re-Programming Quick Tip
How do I change the battery in a wireless keypad?
There are several different styles of keypads and therefore the steps on removing the battery cover are different, below are the instructions on how to remove the battery cover for each style. Please keep in mind that it will take quite a bit of force to remove, but do not worry about breaking the battery cover, as it is designed to be removed this way.
The older style keypad has a screw holding the battery cover in place. You will need a Phillips head screw driver to remove the battery cover, once you remove the battery cover the battery cover should slid off.
The second oldest style keypads have a pin hole at the bottom of the keypad cover, you will have to insert a small Phillips screw driver into the small hole at the bottom of the cover and gently pull outward to loosen and slide the cover down to remove.
The current style keypads have an oval cut out on the top of the battery cover. To remove the battery cover, insert a flat head screw driver in the oval cut out and apply pressure on the screw driver against the battery cover and slide the battery cover down then remove.
Source: How do I change the battery in a wireless keypad?
Please consult your owner’s manual for complete instructions and safety information before starting any projects by yourself.