Replace fresh water tank?

Has anyone replaced a water tank on a sundance? Ours sits on L-braces that are welded in place, so it would probably have to come out from above. How difficult is this? Thanks for information.

If it were me, I would cut the L braces to remove the tank. When replacing the tank I would buy longer angle iron and use self drillers to screw the angle braces directly to the frame. No need to remove it from the top.