Be careful with those springs when dissembling any of the fasteners relating to it. I have done repairs on an old pop-up and it can be done. Just be sure to understand the physics of the spring loaded system and the mechanical actions it imparts.
Also look at all the fastening points. Below is my response to others that have asked about pop-top repairs.
This is my canned reply about pop- ups:
The one thing that I would keep a close eye on the pop- ups is the mounting plates at the rear of the top portion of the pop- up roof. The easiest way to see what I will describe is to look at it with the roof about 1/2 way raised. Have someone inside to keep in in this position while you inspect so that it does not fall on your head.... Look at it from the outside at the rear. Push in the fabric and look at the underside where the metal plates attach to the ceiling portion that raises. You will see what looks like plates that are attached to the top roof. There are screws that fasten the metal plates to the wood. Keep an eye on these!
I had one where the screws gave out from rotting wood and they rotated up penetrated the metal roof
I ended up fixing this, but it was not an easy shore as the tension of the mechanism was tough to overcome to bring the plates that rotated back into proper position.