Cut the old one off, and secure it like jim has done, but i took mine a bit further to make sure it dont flap about

on the bottom of the new grille are little slats, i cut slats in the bumper so that they could slide in, i then used a hot glue gun on it to make sure they dont budge and made a bracket out of a small bit of aluminium so that it had a nice shape all the way round the grille
