For a straightforward single-panel job: we take tension off the door, unbolt the end hinges and stiles holding the damaged section, slide it out, and fit the replacement before re-hanging hardware and checking the door runs square in the track. On a steel sectional door from the 1990s era that's common here, this usually takes one visit once we've confirmed the match ahead of time. If the track is bent or the opener's travel limits need resetting afterward, we handle that in the same stop. What it doesn't involve, if the rest of the door is sound, is replacing panels you don't need replaced - we price the section that's actually damaged, not the whole door.