uhhh I hope you know what you are getting into...this isnt an ammature job. Its alot of work..and I HOPE that they are at least RS quaters. the best advice I can give you (from growing up watching good body men work) put the new quarter next to the old one to see where it needs to be cutthis will give you a starting point...you are gonna have to grind off the paint where the quarters get welded anyway (ie the door jamb) you will see where it was welded in the first place. And you are gonna have to cut all of the tack welds on the inside and underneigth the car. Its alot of work...Im telling you...you have to make sure all of the spacing in the door opening is the same and the trunk also. Plus the striker pin for the door to close. Im just saying that if you are asking a question like: "how do I get the old ones off?" and "where would i cut? and would i have to weld the new ones on?", this might not be a job for you. IF you do attempt it...get it clamped into place and get everything lined up...then put a few tack welds...and KEEP CHECKING IT, before you weld it on completely. Best of luck to you!!!
the quarter panel on the car is also that panel that goes to the side of the roof.. its not only the quarter panel.. you have to cut the part off you have a replacement for and weld in the new piece and use bondo and crap like that to smooth it out
Sounds to me like you shouln't have bought the rear quarter panel, you should have bought a whole new chasis. By the time you could personally measure, cut, grind, weld, grind weld, grind, bondo, sand, bondo, sand, paint, sand, paint, sand, paint, sand.... you could have just swapped everything over from the old to the new.
Ok, you are putting on the fender flares. If they are metal, then the old ones will be cut off and these welded on and smoothed, lota work. Fiberglass or plastic, the old ones will be cut off or covered and blended in.