I have a 2005 rockwood 8318 and I have to get to the Black and grey water tanks. There is a cover enclosing the underside of the trailer, I went to a local RV dealer to get some info, and they told me don't worry just cut it out like they do it will be fine, needless to say I walked away quickly because this advice just did not sound right. Is there a proper way to remove this cover so I can get to the tanks. Thank you George