Help: leaking hot water heater

Hi. Had our Sunseeker de-winterized. The shop said the water heater wasn't working and asked if we wanted it fixed. We said no because we've never used it.

Got to our campsite, hooked up the unit to the hose ... and water is coming out of the heater. The anode is out.

Is there a way to either bypass the heater or does using the fresh water tank avoid the heater?

We're not remotely handy and don't have the tool to tighten the anode. We tried doing it by hand but it's not screwing in.

Thanks!