Seat Belt Problem!

My driver's side seat belt does NOT retract back into the seat belt slot that's located behind my seat on the inside of the driver's side rear quarter panel.
The belt is "twisted". The twisting is towards the end after the belt is pulled to its full length all the way out. I took it to Ford and the mechanic told me that the belt is twisted deep inside the plastic moulding that's on the interior on the inside of the driver's side quarter panel. He told me that I will need a brand new driver's side seat belt because he is unable to unravel the twisted seat belt when he pulls it out all the way to its maximum length.
The mechanic told me that he will need to take off the rear left plastic moulding on the driver's side which is above the rear seat cushion.

I would like to know exactly which parts will need to be disassembled and stripped for the mechanic to get to the seat belt to put a new seat belt in? Is this a big job? How much of the interior will get stripped to replace the seat belt? Will the rear seat cushion have to come out and which plastic mouldings will need to be disassembled to replace the seat belt?

I am worried that I will have loose mouldings and "fit" problems with the interior after the mechanic puts everything back together again after he takes off the plastic mouldings to get to the seat belt. I am also concerned that the mouldings will be loose. Exactly which interior mouldings will need to be taken out to do the work. Should I have Ford fix this problem or should I just live with it for fear of the mouldings being loose and having fit problems after they are taken apart and put together again?Do they have to rip out the entire interior to fix it? I was looking in the back seat area and there is a LOT of plastic moulding along the inside of the left rear quarter panel. WIll they have to take out the seat cushion and then pry off the plastic moulding above the seat cushion that goes all the way up to the small triangular side window and to the head liner in order to get to the seat belt? Will they also have to pry off the plastic moulding that runs along the inside of the running board which connects to the moulding which is located above the side of the seat cushion?

I am afraid that if they have to pry off all of these mouldings that they will be loose after they put everything back together again. How much tearing apart of the interior will they do in order to take out the old seat belt and put a brand new one in?

If I decide to get the work done, it will be covered by my Ford warrantly.