How can I remove broken rubber spark plug wire tip from spark plug in engine

What is your question?

I was checking my spark plug wires and pulled one out and the tip remains stuck in the engine block. My socket won’t go over it to remove the plug. I am trying find out how to remove it.

What makes this problem better or worse?

makes the engine run rough and miss a lot

How long has your 2000 Subaru Outback had this problem?

two days