To open a garage door manually, first ensure the door is not locked and then disconnect the opener by pulling the emergency release cord, typically a red cord hanging from the opener mechanism. Once disengaged, you can lift the door manually by gripping the handle at the bottom. Use caution, as the door can be heavy.

Manually opening a garage door requires disconnecting the door from the automatic opener by pulling the emergency release cord. After that, the door can be lifted by hand, but caution is needed as the door may be heavy depending on the size and spring tension. This is a useful method when there's a power outage or if the opener malfunctions. Having a well-maintained garage door system can make this process easier.