O.K...I give up. I bought the sig night sights from CDNN for my XD-9 They are nice(a heck of a bargain for $24), I can't wait to get them installed. What In the wide world of sports do I have to do to get the rear sight off. I have it in a padded vise and have beaten the tar out of it with a 5lb hmmer and a brass punch and it doesn't even budge. Any suggestions??