Intake air screen removal

[40cpe]

I have a Gravely zero turn with a Kawasaki FX691V engine. I have adjusted the valves and while I was at it wanted to remove the cooling shroud to clean the head fins. The intake air screen that rotates with the fan has hex head screws to hold it on. A metric 3mm is a loose fit and 4mm is too large. A SAE hex key doesn't fit any better. The 3mm hex key just slips in the screw head. I'm looking for a solution to get them out. Thanks in advance for any advice.

 

[Rivets]

I have found that sometimes using a torx wrench will grab. Not best way to do it, but sometimes you need to think out of the box.