This is a typical happening with AKG’s CK1 capsules.
It’s not a big deal.
Get yourself a really fitting screwdriver (they are sold in sets for a few bucks in every hardware store), something like in the attached picture.
Very nice is the bits-set in the 2nd picture.
Doesn’t need to be very special.
The screwhead is 1.3 mm diameter, 1.5 mm driver does NOT fit.
The slot is on the narrow side.
Typically a 1.2 mm driver does fit and work.
Turn all screws counterclockwise until they fit, don’t overdo it.
Remember they are small, not much force needed.
Don’t force anything here!
The screws make the ground connection to the diaphragm, so don’t use any securing lacquer, as it might isolate the screws.
Important:
Stop to wiggle around the head, the diaphragm will come loose and the capsule becomes unusable.
There’s only a small brass ring between the housing and the capsule edge where the diaphragm is glued on, and the glue is old now!
For the same reason, do not open it.