Color Skopar 35 PII loose focus tab.

My Color Skopar 35 2.5 PII focus tab is loose. Took lens block out. I could see how it is attached, but it is under top flange and I can't get to screws with regular screw driver.
Maybe someone knows how to?

UPD:
I get to it. Not sure if I'll be able to get it all back...