On the garage door center track there should be a rope hanging down. Pulling on that should release the door from the track. You can then manually open the door.
The "wire lines" on the "cylinders" you mention sound like what you are describing are springs that connected using wire rope. These springs help lighten the load on garage door opener. if they are not connected the garage door opener won't have the power to open the door.
Code:
http://home.howstuffworks.com/how-to-repair-a-garage-door.htm