We have a 2012 3585 RL bighorn. Water puddle coming from under the shower in bathroom. Opened up basement and crawled over all the electrical plumbing hot water heater to find shower drain line placed between 2 walls. No access. Talked to heartland said should be able to reach hand in. That does no good how do you undo and replace drain if you can’t get wrench in. Told maybe I could remove the wall where the control panel is located.. I would have to cut a hole in it. Does anyone have any ideas . Attached photos.