/diy/ - Do It Yourself

Hey /diy/, I've got a fan in my room that I'm unable to change any speed settings one. The dial started to go a bit funny a few weeks ago but yesterday it completely came out.

I've tried to take the casing off the fan, all but 2 of the screws were just normal flathead-screwdriver ones, but there's 2 left in there.

They look like pic related, but the dots would actually be lines that extend all the way out of the screw, leaving metal still in the middle (so a normal screwdriver won't do the trick).

I've never seen anything like it before, I'm wondering what I can use to try and get it out.

Any suggestions?