I assume you are referring to the freshwater tank. There's a valve you open under the fresh water tank. The freshwater tank is the white/opaque one. You will likely have to scoot under the camper a bit.
Assuming you do not have an instant water heater, there's bolt/anode rod you remove, accessible from the outside behind the wh pannel.
You should determine what kind of water heater you have and find the manual .The camper should have originally come with manuals for the camper and all appliances. If they've been lost most are available online. LL manuals are at: https://www.livinlite.com/owners-manuals/
Assuming you do not have an instant water heater, there's bolt/anode rod you remove, accessible from the outside behind the wh pannel.
You should determine what kind of water heater you have and find the manual .The camper should have originally come with manuals for the camper and all appliances. If they've been lost most are available online. LL manuals are at: https://www.livinlite.com/owners-manuals/