To do that is not impossible, but it would take some work. You would have to drop the under belly and then remove the tank and ten put the under belly back on. Make sure taht they did not just disconnect the fillspout and lines to the pump.
This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.