a clip on the fuel door assembly ((77305-30020) holds gas door filler in place) has broken off. Currently I have the filler held in place with a sheet screw on bottom, and some dbl sided tape on top.

Anyone have a good idea of how to remove the old, and fit the new in place? Is it attached around the filler neck behind the panel? Looks like on the 07 its accessed via trunk? It'll be a few days before i can get in to look at it, but trying to come up w/ a game plan. Lexus wanted $800 in labor to replace.
Thanks,