I might try Tony's suggestion

Actually, customsex made the suggestion before I did.

I was just worried about stripping them.

In my case, the screwdriver would get damaged before the screw would. The jeweler's screwdrivers that I was using were pretty small and fragile.

I dunno what the screws are like on the WaveBird, but on the regular controller, they were easy enough to get in and out with the jeweler's blade that I didn't bother with finding different screws when the job was done. I just put the triangular screws right back in and made sure that they weren't super-tight.