We had a new front door and storm door put in. I was smart enough to realize I wanted a pro to do it. It was amazing to watch him work. He had a helper that was a step and fetch it guy and extra muscle. He took down the old door & threshold and had everything back in place in short order. The first thing he did was throw away the instructions.
All new locks and hardware hung perfect so it closes the way it should is just a few hours.
My only part was going to the door place and hauling it home and setting up a place in my garage so my wife could paint it before the door guy hung it.
It is a far better installation than the builders door.