I have a pair of 1979 Asnes cross-country skis with Rottefella 75mm NN three-pin bindings that I plan to upgrade to NNN. The toe piece of the binding is held on with three screws that are easy to remove. However, I can’t see how to remove the heel plate. It only appears to be a short steel post through orange plastic with no visible screws.

The plastic appears to be held on by the post alone (like a rivet) –I can rotate the plastic around the post with my fingers. Do you just pry off the post with a screw driver? Or drill it out? Or what?