Cutting up a Storm Scout side panel...advice requested :-)

So, I've had a Storm Scout case for about a year or so now (named "Bizzaro Stormy", after the Sealab 2021 episode "Bizzaro"), and I absolutely adore it...but one thing has always really bothered me about the side panel. In case you don't know what it looks like, here you go:



You see how the two mounting sections for the fans are slits in the acrylic? Well, the reason why this is a problem is if you put a fan in there that moves more than .0001 CFM, you get this INSANELY annoying whining noise. I've tried 5 different fans, I've even tried using those rubber "no-screw" mounts for fans...no good. Air coming through those acrylic slits causes a whining/wooshing noise.

So. I would like to snip these slits out (except for the ones with the mounting holes) (boy, doesn't that sound dirty!) and just use regular fan grills to help protect fingers and pets. I unfortunately only have access to basic hand tools...anyone have any suggestions on how I can easily, cleanly, and cheaply snip those slitty bastards out of there? Thanks!

I would use a scorer, or xacto knife and work over the cutting point. Then using a tool like sharp garden shears or a metal cutting scissors snip them close to the score. Then finish up with a nail polishing file.

Interestingly enough, I have all of those things. Thanks for the tip! I think I'm going to do it that way.