Question cpu backplate screw size for hp envy 750

Sep 1, 2019
I have an older computer, an HP Envy 750-409, with a low profile CPU cooler. I intend to replace the cooler.

Does anyone know the screw size for the backplate so I can mount a new cooler?
I couldn't find a decent HP manual online.

I recently purchased a Be Quiet Pure Rock Slim.
The cooler looks great, but it came with those plastic pins, and the earlier cooler was screwed in.
I tried installing the cooler with the pins for quite a while and I believe the OEM mobo backplate is interfering with being able to use them.
So I've removed the plastic pins from the cooler (I hate pins anyway) and want to use screws.

The screw looks like a 6/32, but I was expecting an m2 or m3 screw size.

I am hoping someone knows the proper size, because with the current covid crisis going on, it will be more difficult to get to a hardware store and track down the proper screw size.

Thank you.