You don't need to mess with any wires on the inside. The output is just a 12V square wave whether it's the original setup or cut down to 1 vane.
Red gets ignition +12V
Black gets signal ground
Green would be the square wave signal positive going to the Terminator.
If you look at the pic
here that's pins 1, 7, and 8 respectively on the distributor's connector.
I even suspect you don't need to cut any vanes. One of the vanes is a different size to represent cam reference, so the signal technically already contains a cam signal. The question is whether Terminator X is able to recognize that as a cam signal or not. Since the official Holley Hyperspark distributors have the same sensor and "one vane is smaller" setup as the stock Ford TFI distributors, the rational assumption is it should interpret the unmodified Ford distributor vanes as cam sync if you tell the Terminator software that the cam/crank sensor is a Hyperspark. But, I don't know for certain that it does interpret the Ford/Hyperspark smaller vane as a cam signal. If Holley's TermX can't interpret their own distributor's cam signal then that's just lazy of them...
If it can't interpret Hyperspark/TFI's small vane as cam sync (ugh - that would be silly of holley) then in the worst case you can cut the vanes and then tell the TermX software that the cam sensor is a single pulse signal. (falling edge, I think). Still no wiring change in either case.