You can view this video on how to safely open your garage door with no power here.
Manual garage door stuck closed.
Once the lever is disengaged you should be able to open.
How to close your garage door by hand 1.
Garage door locked surprisingly your garage door just being locked can be causing your problem.
A garage door stuck in the closed position may tempt you to crash on through but don t let frustration get the better of you.
If it is possible to safely pull the garage door manually to a closed position before attempting any repair do so.
Locate the emergency cord on the overhead track of your garage door opener.
Some garage doors have a full lock system which enables you or anybody to lock your garage door from the outside by only turning the handle.
When attempting to fix a garage door that is stuck open make sure to turn the garage door opener off.
However if you encounter resistance stop.
Advice guidance steps to follow and information on what to do when your manual garage door will not open the one thing that can be virtually guaranteed in life is that if something is going to go wrong it will occur at the time you least need it to happen.