Please be gentle as I am new here.The plan is to operate a 120 VAC device off by sending a momentary pulse of 24 volt DC current to a AB HJ series latching relay. The relay coil however requires a reverse polarity pulse to unlatch the relay.I am using a simple step on switch which lays on the floor to send pulse to relay. The boggle remains how to reverse the polarity (simply) to unlatch and then reverse again, when I am ready to start again.

 

Where are you getting the 24 volts from? If you have your own supply from ac just make a reverse polarity side. Some latching relays will open if the circuit is broken briefly, but yours does not seem to be of that kind.