Two springs replaced: $285 for three hours work by a friendly guy with 21 years experience.

The dead weight of the 18 ft by 6 ft 10 inch door was measured to be 351 lbs.

If I had not witnessed it with my own eyes I would not have believed that those two heavy helical springs could be bent around 360 degrees one at a time like huge pieces of stiff pasta in order to remove them both from only one shaft end with only scant 9 inches of clearance over to the wall.

I thought the top shaft would have to be completely taken down,
set on the floor,
and turned 90 degrees to remove the old springs and install new springs,
then lifted back up and re-mounted.