Doornkaat wrote on 2021-01-25, 15:59:

It's a stupid mechanism. You need to press down on the large tabs to unhook them and then simultaneously pull the far out side of the large tab up/to the side so you bend the hook away from the retention frame so it does not hook in again when you stop pressing down on the tab.

You're not the first to have this problem.😉

You could also push on the tab to unhook and use a flat head screwdriver to pull the little hook from the plastic retention frame.

Anilocin wrote on 2021-10-29, 15:37:

Hello Everyone,

I've been struggling to remove this AVC S478 heatsink as I'm trying to upgrade my P4 AGP test bench from 1.8 to 2.8 Ghz. Old forum pages state to push the two AVC-marked metal tabs down, yet the heatsink doesn't seem to loosen up. Any ideas?

Thanks!

Which is correct. Prush them down and pivot back for them to disengage.

Anyways, I have been able to remove the metal latches, with brute force I pushed out the tabs with two flat-head screwdrivers.

Thanks for the help! 😀

All is well that ends well.😉👍