I have a friend with a set of XXtwenty that are beat to **** that he'd like to rejuvinate with a new lens. How do I get the old one out? Oakley sells replacement lenses for the fully framed glasses, but I was always under the impression they were not removable. Oakley XX Replacement Lenses available online at Oakley.com I haven't had any luck finding this on the forum. Also, are the X-Metal XX the same lens as the XX Twenty? Thanks all!