2 Before the new skin can be installed, the original door assembly needs to be hung on the car and made sure it will line up. You also want to look for issues with the inner door structure, like cracks around the hinge attachment points. If there are a few small cracks, those can be welded up. But, if it’s pretty bad or shows signs of damage from a crash, you might want to look at purchasing an entire door not just the skin. This door passes all the checks, so Craig can continue with the job.