Is your garage door opener remote being stubborn? Do you have to press the garage door remote buttons multiple times to get the door to open? Most likely your garage door remote battery is on the way out. It is very unlikely the remote is broken and if the door is completely unresponsive or hit-and-miss, the remote battery is the first thing to check. Considering how simple it is to replace the battery, you should go ahead and do so before the garage door remote goes out completely. Be warned that most remotes need to be reprogrammed after the battery is changed, so make sure and read this entire guide before proceeding and/or call your local garage door repair service for help.
Flip the garage door remote over and you'll see a cover on the back that can be removed. If there is no obvious cover to remove, the whole remote housing may just split into two pieces. Usually you can remove the cover or pop the remote open by simply pressing and sliding the cover. Sometimes there is a screw holding the cover on. If this is the case, you'll likely need a small screwdriver. If your screwdriver is too big, you may need an extra small screwdriver such as those found in glasses repair kits.
The battery is commonly a flat, circular, coin-like shape. Sometimes it is a very small alkaline, but rarely. The coin shaped batteries typically simply slide out or pop out. Take the battery with you to the drug store or auto parts store. Someone will be glad to help you find the match, but the battery type should be clearly printed on the battery itself. It is usually a short arrangement of letters and numbers, like CR2032.
Insert the replacement battery and replace the cover in the reverse steps you took to remove it. You will likely need to reprogram your remote at this point. This is easier than it may seem as modern openers come with a single button for pairing your remote, though older openers use dip switches for pairing the remote. Find the model number of your opener and look up the manual in your files or online. The manual will show step-by-step how to program the remote.