Installing an opener on a door that already has working track and springs is a half-day job in most cases - the hardware is already there, so the work is mounting the rail, wiring the wall control and sensors, and setting the force and travel limits so the door doesn't slam or stall. Where it gets longer is when the original torsion hardware on a 1998-built door hasn't been serviced since the house went up. Springs from that era are rated for a certain number of cycles, and 25-plus years of daily use runs most of them close to the end, so we check spring condition before we hang a new motor on old hardware. There's no point putting a new opener on a spring that's about to break - you'd be back to a stuck door in a month, and the opener gets blamed for a spring problem it didn't cause.