Hi Phil
With regards to the removal of the front seat belt reel from your 4 seater, you will need to remove the centre consul form between the rear seats. The fixing top bolts for the rear seat belts will have to be removed, and then the centre consul trim will lift up, check to see it the are screws in the front lower edge under the carpet.
Once this is up out of the way you will need to jack the car up and put it on stands, at this point you will need two people one under the car and one in side to undo the reel securing bolt.
Undo the other seat belt mounting bolts and the seat belt can be withdrawn.
Good luck
You do not need to cut any holes in the car to remove the belt, just remove centre consul.