Those are screws that can be removed with a torx bit. I have done this before but gave the heatsink away so I can't deliver proof.
Maybe you can post pictures of the screws here after you removed them so we'll have facts instead of opinions. 😉

They look more like hex than torx to me, either way you should be able to unscrew them

Thanks, need to find an allen key then .. The T10 torx was too big to fit, T9 was too small, so hex seems plausible ..

Facts? It's the interweb, we don't need facts 😉 🤣

Will off cours post pictures if succesful 😀

I tried it with hex but it didn't work well and stripped the hole of the first screw almost round. Torx needed to be pushed in with a bit of force but worked fine then. Hence my suggestion to use a torx bit.
I don't think the screws were torx originally but torx works because it has better grip. You can see they used a tool similar to torx but probably slightly pointed to apply the screw from looking at the way the metal is bent away from the center (exaggerated in pic).
Regardless of what tool you use I hope they come out fine. 😀

Well, the hex shape worked for me. A 2 mm allen-key, a pair of pliers and some more force than I was comfortable applying to that 2mm key, which was almost a quarter of a turn bend, before the "screws" loosened.

I read somewhere a description of them being something between a screw and a rivet (like a screw, that is riveted in place), and that if replaced, the screws should be replaced in the holes they came from. Which seems reasonable, as the thread is pretty damaged - actually I would say, that there's no way they are reusable.

Thanks for the input, here goes the promised image:

I've come across these, they are a real pleasure to work with, as is the case with most Intel heatsinks. They've spoilt us, for sure 😀

I wouldn't try to reuse them, as there is barely any thread left. If you're about to dismantle the entire cartridge for cleaning and applying new thermal paste, I'd suggest re-threading the holes in the spreader and enlarging the ones in the heatsink and use normal screws instead. M4 should work fine.