How do I switch the fan on the side panels of Chieftec cases?

OK, so i have a chieftec matrix case and wanna switch out the fan that's in the side panel for a higher powered one(it's pretty weak). The question is how do i get the fan that's on there now, out? It's got some funny looking things on it, not your usual screws, i don't know. So could someone please help me out with this?

thanks,
Kent

Are they black and have a pin sliding through a hole? If so just push the pin back and they should slide out

i have a chieftec case with a window and mine is screwed on. pictures maybe?

toddm27 got it, thanks

Kent