Fresh water tank leaking in new Lance 855S

The weather is warming up here in Portland Oregon so I filled the fresh water holding tank on my brand new Lance 855S for the first time one week ago. As it is new, I threw in a tablespoon of granular chlorine to disinfect the tank. The camper has been on my truck and driving around for the past week as sort of a shakedown test and to slosh the chlorine water around in the tank. This weekend I took it off the truck and when I did so, water ran out of the truck bed and from under the camper and it smelled of chlorine. I checked the low-point drain valves and they are closed. So, it appears that the fresh water tank has a leak ... heavy sigh.

It has to be the fresh tank as the grey tank only has a little bit of antifreeze in it.

What must be done to access the tank? I hate the idea of some RV service dude ripping into my new rig. Can I do this work myself?

Any thoughts or advice greatly appreciated.