what it takes to get the old Brake Light Switch off so I can install new one?

What is your question?

The Brake Light Switch has to be removed so I can install the new one! I have unplugged the wires. But, a short shaft goes through the two holes, and something has to be removed. It is holding the old part on, Ut nat be a key, or pin, or ring, or something to release the part so it will come off, so I can install new part! Hope you can answer my question?