Draining my fresh water tank

[1999gulfstream!]

I have a 1999 palm breeze. There’s something wrong with the plumbing system. None of the facets or water work unless I’m hooked up to a water hose....

I want to drain my freshwater holding tank. Is there any way to do this?? Also if anyone has any insight or troubleshooting recommendations to get my water going, I’m all ears!! All the water pumps just stopped working one day