You have to cut it apart carefully (so you can rejoin it after you''re done) - this plastic is very brittle and unforgiving to mistakes. Then you remove all the old plastic mesh by cutting it out and sanding it down then you trim the new mesh to fit and sandwhich it between the two halves of the grill, then join the two halves back together. I have seen some people do it themselves. Some do it well, the others - well, you can see they f'ed it up bad. Y2KSVT gave up after trying to do it himself and ende up sending it to me.
