The only connection to the card other than the PC Bus is a thin wire with a connector on the end. This wire plugs onto one of the motherboard pins that go to the Reset button. You can either remove the cable that goes to the Reset button or splice into it. If the RPCR does not function then try the other one in the pair. The RPCR signal is an open-collector transistor so relays, indicators, and other devices can be activated instead of Reset if necessary.
Testing is simple.
With no special software running and the RPCR installed the computer will reboot once every minute or so. During normal operation the RPCR is cleared at intervals of less than one minute to keep from rebooting. These programs normally tickle the RPCR to prevent reboot but will intentionally lock up the computer when a key is pressed. Otherwise a minimum service charge is required.