To get the car ready to go the frame shop I had to take out the interior. Well, it saved me $150 to take out the interior myself. Overall it was not all the difficult. There were a few sticking points, but with some patience I finally completed the removal and then reinstalled the driver's seat so that it could be taken to the shop.
Here are some pictures of the floor pans and interior in general.
These are things you want to look for BEFORE you buy a classic mustang. The front floor pans have extensive rust on them. The rear floor pans are missing sections and has several very cheap repair jobs on it.