[Jabberwocky]

Most of the endpin jacks are Fishman or Schatten. I am just guessing that it is a Schatten. If you look them up you can find diagrammes that will give you an idea of how each one is installed.

I would suggest that you remove the pickup and leave the endpin jack in place. For one, it leaves a big hole in the rim where no standard endpin fits. For two, you or the next owner may decide to install a new pickup. The endpin is already in place. For three, now that it has been reamed out for the endpin jack it is structurally stronger with it in place.

I don't like these endpin jacks but I leave it in place when the guitar comes with it. I would also leave a sufficient length of wire for an easy installation of a pickup should the need arise. Just fold and tape down the free wire to the end block.

IMH Great Unwashed Opinion.