I use a small flat head. I usually find a place in the head or cabinet nearby to set the connector on. Then with one hand push in the tab with a screwdriver and the other hand pulls the wire out. Takes a bit of practice and then you get good at it without mangling the housing.

If you are repinning the entire plug, the only connector housings worth reusing are the really long ones in a bally game that you can't find anymore. They are cheap enough i usually just use a new housing to save the step of pulling the contacts out of the original housing.

I can't find any larger than about 14 or 16 pins i think its. Bally used some 25's, 28s in .100" and up to 20 in 1.56".

Sure you had the correct size?? Sometimes you have to push pretty hard on the round pin extractors to get it to slide overtop of the locking tab.

they made a lot of early bally ss games