Positive to Negative Conversion for Mastercell

I am using the Summit Raptor Pro to provide much of the switching via the steering wheel. I need to have the inputs to the Master cell be ground based. I know I saw it somewhere, but can anyone point me to the wiring needed to convert the wires that normally attach to the GM steering column into ground based feeds?
You can also take a relay and set it up as a negative relay.

There are numbers on the relay posts but you can also test for the switch circuit with a 12V battery and listen for a click.

Input of switch circuit on the relay: Positive from Raptor Pro (85)
Ground the other wire of the relay switch circuit (86)
Connect one of the other two relay circuit wires to ground (87)
The other wire will be the output which will now be a negative signal. (30)

85 - 86 is the switch circuit
87 - 30 is the circuit which is being turned on/off by the switch circuit