Replaced one of my garage doors this weekend. This one got stuck a few
months ago. I kept increasing the door closing and opening force not
realizing a pulley went bad. It eventually bent the top panel before I
found the culprit and replaced the pulley. I fixed the bent top panel.
But it did not look the same. I finally relented this past weekend
and bought one from Home Depot, a standard stock fully insulated door
for a mere $414.

Brough it home Saturday morning. I was all gong-ho with my air wrench
starting to remove the closed bad door.

Now if any of you have not removed a garage door before, please, please
do not do it with the door closed. Do it only with the door open and
when there is no spring tension. I was lucky I didn't get killed.
When I removed the last bolt on the bottom roller attachment on the
bottom panel, the bracket, hooked on the cable pulled by one of the
springs, flew up and made a big hole on the celing plaster in the
garage. God had mercy on me. If I were a few inches closer to the
door, it would have taken out my face.

After the near miss there were no more hair raising incidents. Except
I made the usual mistake of just dove right in without looking at the
installation instructions first. The second panel from the bottom
where there are prepunched key holes ended up being installed at the
top which I had to redo. I also got lazy not wanting to remove the old
tracks only to find out the old tracks were shorter than the new ones.
So the top panel of the new door would not close to seal the opening,
which I also had to redo.

Overall I think I still did a fairly decent job. The installation
instructions say it takes 9 to 12 hours to install one door. Despite
of my blunders, I came in just under 12 hours. It included two trips
back to Home Depot first asking them why the door won't fit (because I
used the old tracks), and then why the door won't close (Which they do
not have an answer for. The new door closes and come back up. My
younger son suggested hooking the opener attachment to the second hole
on the top panel which solved the door coming back up problem.)

Still I am not clear how the two adjustment screws on the opener
functions if I had to troubleshoot again. Could someone explain to me?