One of the cables snapped when the orleans garage door repair was going up. Door is now open about 10" with one side being a little higher. The cable on the other side has come off the drum and is wound around the shaft. How to I go about getting door back in the closed position so I can change the cables? Do I replace the broken one first with the door in its present location and work from there or? Have worked with doors before (rollers changed, hinges replaced, panels) but was a functioning door when I started.