My key sometimes sticks in the ignition tumbler so I'm trying to replace the tumbler. From what I see in the new tumbler, there's only one spring tab to compress before the tumbler slides out. I've tried various combinations of 2mm drill bits and 2mm hex keys but I can't get the old tumbler to release. I even humored the manual and used two devices to simulate the u-tool. No amount of tugging will release the tumbler.

What am I missing?

Thanks,
Sixto
91 300SE
87 300SDL
81 300SD