The only rust out spot on my truck is the LF fender so I cut out the rust & butt welded in some 16G metal patches. I need to get behind the plastic fender liner to get some paint & under coat.How do I pop out the plastic retainers. Mine look like they have rivits, so after I pull 'em they're probably toast right? Just cut the heads? Where do I get good ones that hold this well? I bought others that just slide in and are like shredded but don't really hold well. What do you all use & get them?I used those cheapie ones for my stock air filter cover base & they don't really hold that well! I don't what my liner falling while I'm driving!Thanks,Dave

Stop by a body shop they show stock these kind of fasteners...

Try pushing the center in, it should go in about 1/8" or so, and then pulling them out carefully. You might need to use a screwdriver to push the center in. If you are careful you should be able to reuse them.

I don't know if these are the same. Dodge used some plastic "pop rivits" they call "retainer" part number 34201631. I bought some (dated 11.5.01) then discovered the center was too big for a conventional pop rivet tool... they look to be about 1/4" D X 1 1/4" long. I'd suggest installing an anchor or a blind nut & using a screw. I still have 5 in a package.