A full installation means pulling the old door, old track, and usually the old springs and cables, since reusing twenty-year-old spring hardware on a new door isn't worth the risk. New track gets set and leveled, new springs sized to the new door's weight, new rollers, new cables, and the panels themselves go in section by section with the opener reconnected and balance-tested at the end. If the opener itself is original to the house, that's worth discussing separately - a motor from 2002 is past the point where most manufacturers still stock parts for it, and running a new door on an old opener often means the opener becomes the next failure point within a year or two. We'll flag that rather than let it become a surprise.