How to reuse push-pins after changing fans

I am replacing the 2 pin 80mm fan with a 3 pin 80mm fan. The original fan was attached using these plastic push-pins which I presume help dampen the noise.

I am not sure how to reuse them.

The way they are now, they are too wide to be pushed in. Are these one time use?
Or do I use a plier to squeeze them tight, and then push them in?
Or is there some other secret.

they are kinda one time use... you can push them in and re use them if you want to... but why, they dont help with noise reduction, the only reason to use them is to shave a few seconds off assembly time vs. using screws. brand new they are closed, insert, and push the button home... once they have been used, that time saver is spent, and might as well use fan screws.

Thanks for the insight Thor.I did not realize you could pull and push the top.
There are two kinds of pins in the picture; one with the pulling mechanism and another without.

I tried using the screws which came with the fan, but the fan holes are not threaded and it is going to take some effort to put them in. I might as well use a plier and compress the pins.

Playing with the pliers, I realized that the pin comes out completely and the two which looked like they did not have a pin, also had one. Removed the pin, inserted the remaining washer thingy, pushed the pin back and it was easy

Yeah those aren't so bad if they are newer. I've seen those used mostly for car panels. Problem with them is that the little legs break off easily when they get old and weathered. My 16 year old car panels are currently being held up by 3 of the 15 available because they all broke.

Not hard to put back if you haven't figured it out yet. Keep the pins out and squeeze the little legs together then put it into the hole. When you get them positioned right then push the pin back in and they lock in place.