Rollup doors up to 10×10 can usually be installed by two people, without the use of a lift. Anything larger will require a lift and minimum two people to install.
Track and stop repairs are fairly simple and straightforward, however caution must be used as the door and curtain can spin out of control and cause serious injuries if it is not properly secured during the process. In most instances the tracks are attached using some type of tech screw or masonary screw, if it is welded it presents a more difficult scenario as the welds must be ground off and the new tracks re-welded.
Spring replacement requires removing the door from the opening and lowering it to the ground. The door curtain must then be unwound from the spool. The end cap(s) of the spool must then be removed by drilling out the rivets to access and remove and replace the spring(s). The end cap(s) must then be riveted back onto the spools, tech screws can not be used as they will not allow the curtain to wind around the spool properly. The curtain must be rewound to the spool and secured to control the curtain. The door/spool unit must then be lifted into place and the spring loaded by turning the entire curtain/spool unit the proper number of times. The curtain is then inserted back into the guide tracks and stops installed. While the replacement springs are reasonably priced, the equipment needed and the labor and manpower involved make the labor prices go up significantly.
On some of the rolling steel doors it is possible to replace the curtain or a damaged section of the curtain, but again the labor involved and the price of the replacement curtain drives the price up, and this would be more appropriate for the large and expensive rolling steel doors.