It's going to take most of a day to do that "right" because they will need to remove a huge chunk and replaced all the material. Don't believe these people saying a new door will be the same.... A decent exterior door costs $500 alone and install will cost at least that again.

That being said, I'd just replace the door. I recently replaced my front and garage doors myself. It's not as hard as you'd think. I spent like 4-6 hours on each. I did run into some leveling compound (cement type stuff) that leaked in from my flooring that I had to chip out on the front door.