To replace garage door batteries, pry off the casing that covers the batteries, remove the batteries, set them aside, install new batteries, and replace the casing. Required tools include new batteries and a screwdriver. Battery compartments may vary among different models.
To access a battery compartment of a garage door opener, apply pressure to the ends of the casing that encloses the batteries, making sure not to break it, and remove it. Other models may require a metal visor clip to free the casing from the opener's main body. Be sure not to mar the cover.
For a garage door opener that operates with the help of a remote control, gently slide off the battery cover. If the remote control has a screwed-in cover, use a small screwdriver to unfasten the cover, taking care not to chip the slots. Then, slightly tap the device to release the batteries. Alternatively, use a flathead screwdriver to pry out the batteries. Dispose of the cells.
Once the batteries are removed, insert new cells, and reinstall the cover. Be sure to use batteries of the same size and voltage as the old ones, and to check the direction in which to place the batteries. Test the garage door opener. Remove and reinstall the batteries if necessary.