Good Morning Muke, I have a 31' O'day that needed a new set of gears. While I had the transmission out, I drained the fuel tank, using an electric drill and a jabsco pump (you can use an oil drain pump). I then disconnected everything from it and pulled it out. Pretty simple, actually! I put in about a gallon of fuel and "sloshed" the daylights out of it and dumped. I wasn't too bad. I filtered the fuel I had drained from the tank, added a biocide, reinstalled the tank and then he filtered, treated fuel. I'll top off the tank and run the motor to get the treated, clean fuel throughout the systen and am ready for the winter. The companies that I have spoken to use a dialysis machine which will do about the same thing that I did through the pick-up pipe...the only problem is that there is a 1/2 inch space between the end of the pick-up pipe and the bottom of the tank. It leaves sediment on the bottom that it can't reach. It's not a bad job if you have some rags nearby and it is MUCH cheaper than paying to have it done.
