hi to remove the rear 1/4 glass and trim without destruction is easy and hard at the same time. firstly remove the door seal that runs down the 1/4 glass and along the roof line. then unscrew the roof/door trim that the door glass laps under, and gently lower down at the 1/4 glass end. this gives you wiggle room later. then get in the car and unbolt the front seatbelt upper mount and put it on the floor. Next you have to gently unclip the rear 1/4 trim panel upper and lower ( it will be hard) when you have removed the upper trim panel (window surround) then you will have to get a deep 8mm socket if my mem is correct on the size. the nut is at the rear of the car at the point of the glass undo this and there are a couple down the B-pillar these bolts undo the trim round the glass. Get back out of the car and then you will have to gently pry the trim from the car PUT SOME TAPE ROUND THE GLASS TO PROTECT THE PAINT. dont use a screw driver find something plastic that is not very flexible.
once the trim has been removed the glass has to be cut out and special tools are required, not a job for the DIY i use my own glass man at this point. i recommend you do the same because he can bond the new glass in properly then its just a case of rebuilding the car.
take your time the job is difficult but can be made easy by taking your time and getting someone in to take out the glass.
Big thanks gents for the help and advice. Looking at the car as from what you have said I think that I will leave the glass alone, if I could just remove the trim that will be enough I think to do the small amount of paint work that I wanted done, will take my time and see how it goes.