Bulkhead connector

The ones I have are individual tools. Sometimes they are all linked together on a cord & sold in a small box. I think it's easier to use an individual tool than an all-in-one tool like the one pictured, but they are what is used most to detatch most of the connector wires/pins from the connectors themselves. It would definitely be worth having one of those, even if you only use it once in a while.