I have finally tracked down my sewer odor to the waste macerator pump next to the tank at the stern. There appears to be a tiny amount of seepage at a seam in the housing. This has got to be the most difficult inaccessible part of the boat. I can barely touch the thing The pump does not operate (or is jammed). I have never used it because it's illegal to do so in our sailing area . Is there any advise on how to get this changed without tearing the boat apart? While I'm asking, can the tank come out through the rear bulkhead if I take out the giant plastic trim piece at the back of the stateroom? I don't see any other way of getting to it.