You can remove the antenna without removing the entire fender. You can then weld a patch over the hole and clean it up. To remove the antenna, loosen the bolts that hold the wheelhouse to the fender, and body (behind the tire), block the wheelhouse away from the fender and remove the 10 mm bolt in the doorjam. The bezel, electrical connector and the antenna lead, are next and you can pull it out of the bottom. You can avoid all the hassle of realigning the fender.
1991 OCC 461 (.030 over 454) BBC, 3.23 posi, flash to pass, drop spindles & springs, custom fender skirts, Impala rims, Recaros, Blazer console, MOMO/wood SW w/QR, custom wood shift knob, Pioneer DEH P77DH
1992 OCC now with 5.7 tbi, DEH P77DH
For a parts list, check http://www.impalassforum.com/vBullet...1#post11691762