Cougar 26bhs fresh water leak

[boxer]

Noticed tank was leaking after it was 1/4 full. Took down the black liner. All hose fitting tight, no leaks, small frips were coming from the corners of the tank. Tought to tell but it looks like the self tapping screws that hold the tank braces to the frame might have rubbed through the tank??? How can the tank be removed?? We have barely used our trailer and it has been good all year until now? Does anybody else think that putting shapr head self tapping screws under neath the plastic tank to rub on is a good idea. Our 2012 cougar has been a pos so far and i bought it because i thought cougars were quality??