What is the best way to remove the spark plug wire caps on the dtribution harness?

It's honestly a better idea to just give in and go buy a new set of spark plug wires... You will tear them up and cause a dead short if you try and pull the caps off of the wires... most of them are glued on, and they can't take much pressure if you pull on them... sorry. Just buy new ones, you'll waste less time that way, and they are not really that expensive.