The lever pin is the shaft of the siphon lever and holds the lever in place.

Removal is possible with a pointing tool and hammer, but the plastic of the siphon head can be easily damaged in the process. It is therefore better to press the pin out of its place, for example with a metal pen refill. The more times you remove the pin, the easier it is to get it out, as the bore will wear out slowly.

Replacement is almost never necessary.

Siphon lever pin