123 fuse panel: repair or replace

The A/C fuse housing (#8) is melted. It looks like a bear to replace the fuse panel. I have seen several waterproof fuse holders and was wondering if installing an external fuse holder was a good idea? Has anyone else seen a melted A/C fuse panel socket? Are the wires on the underside of the fuse holder typically damaged if the fuse holder melts/burns?
If the panel does need to be replaced are the wires pulled through the fire wall to ease installation or is the whole job done from inside the car with the dash pulled?