[TL;DR: WHAT IS THIS MYSTERY CLIP? AND HOW DO I REMOVE? (clip located behind FL wheel-well cover - see attached image for reference)

I'm an absolute newbie when it comes to working on cars, but not a newbie when it comes to finding ways to save money, and live better. I have a bone stock '13 S60 T5 that we've had in the family since it was new and has since accumulated 106k+ miles.

I recently sustained some damage to the FL Fender + Headlight (i.e. Headlight got blown to bits; FL fender really not fendering) and thus I've decided to bootstrap the repairs and do them all myself: 1. As an opportunity to learn and dive into a longtime interest/hobby 2. See point about living better above ^.

To that end, I sourced some decent parts off ebay and am in the middle of taking off the damaged FL fender. I've managed to take out all of the bolts/clips which keep the fender in place, EXCEPT FOR ONE. (see clip from hell attached)

Can anyone tell me what this is? How do I get it out? And please for the love of G_d don't tell me I need to take off the FL door or the hood.