What is the glue holding the plastic nut on?

I want a reverse answer to the question so I can remove the block of plastic stuck on my ES builds.

On my ES-3 build, there is a extremely thin piece of rosewood from the fretboard underneath it, if I try the "Would be normal" approach, and just tap it with a hammer, I'm almost certain that veneer will break off with the nut.
As it is, from the bone blanks I've been able to get to create a new nut, only one seems to have enough height to replicate the plastic one.

And that's only if that veneer remains.