If the garage door is fully shut it is safe to pull the bypass cord. Make sure to pull the rope down and towards the back of the garage (or towards the motor) as this will prevent the rope from getting caught on the tracks.
When you yank down on this handle, the automated opener carriage that normally opens and closes the door is released from the trolley. This allows the door to slide freely on the trolley without the help of the electric mechanism.
When you’ve successfully disengaged the mechanism, you will hear a “pop” which means the motor is no longer connected to the door. You should then be able to easily lift the garage door. Using both hands, grip and raise the door from the bottom.
If you feel any resistance when trying to lift your garage door, stop and contact a professional, do not use force. If your garage door does not open smoothly after pulling the release cord, this could mean the door is off of its track, or the springs are broken.
Keep lifting the garage door until it is fully overhead. Without the automated lifting mechanism, the door can slide back down if it is not open entirely. When shutting the garage door, make sure you lower it slowly and manually lock it by sliding the lock bar.
Make sure to keep the rope out of the way when the garage door is in manual mode. Pull it back and as close to the garage door opener motor as you can.
You will now be able to open and close your door manually.
It is important to secure the door by propping it open or by having others hold it while you exit out of the garage as the door may not stay open during manual mode and potentially may come crashing down if the springs are faulty.