Below is a picture of the front and back of my side marker light. What kind of fastener is holding this light to the metal? It looks like some sort of white plastic push rivet.Maybe not a push rivet but it is loose and only spins when I try to remove it. Probably not from the factory. I plan on replacing the worn out rubber and will most likely destroy what is holding this on to remove it. What should I use to hold the marker light onto the car?
Click to view attachment
Click to view attachment

Plastic clips.
Also a really good time to replace the seal.

May be able to reuse if not I have them here -
https://900designs.zoeysite.com/side-marker-plastic-clip


Looks like you may want to replace the boot while you are there too.
https://900designs.zoeysite.com/front-turn-...al-grommet-boot

They can be re-installed with nuts and bolts......

They can be installed with plastic pop rivets too. readily available at HD