Your best bet is to have them straightened at a machine shop. If you know someone with a hydraulic press, that works too. It doesn't have to be real fancy. I've straightened out many rails on mine.
Also, check to see if the rear pivot links are not bent. I was just working on an '01 Edge X, which had, what appeared to be bent rails. A closer look showed that the rear lower pivot link was bent, throwing the whold skid off-square. Other that that, you can find a good deal on complete skidframes at Haydays in Minneapolis in the fall. New rails are $200 ea....ouch!
Unless the machine was totally destroyed, the rails are usually straighten-able.