The addition of fender flares almost always destroys the sheetmetal beneath... plan on the probability of replacing the quarter panels and fenders. Patching the wheel lip areas is one of the more difficult things to do when working the sheetmetal of the body of the car... its a much neater job to replace the entire part. Were the original wheel lips cut out to make more room for big tires? What about the outer wheel houses on the rear? Were they cut? I'd have to say that removing flares is likely a job for a professional.
