Insert the blade of a narrow knife into the insert until the blade just bites into the delrin and turn it counter-clockwise to remove it.
I couldn't find a narrow knife and kept trying to rack my brain about how to remove this. I ended up using one side of a pair of scissors and pressing it down as I turned counter-clockwise. Seems to have done the job just fine!Just be careful you should be fine. Good luck.
Now I just need to order those pieces from Meerschaum Market and I should be up and running again.