On a small bread board or perf  board install the 2 relays and a bridge rectifier, make all connections. Bring out the relay contacts to respective terminal connection points. Bring out the 2 wire connections to a terminal.

Install this board at the remote location.

It would be easy to use a relay socket or a contactor type relay to have screw connection points for all wire connections. Just wire the external Normally Open switch contacts, and  the DC Power source to the relay socket, or contactor relay.