There is a drain plug on the fuel tank but you have to remove the plastic covers over it first.
and there is a manual for the aw11. Haynes make one and there is the infamous BGB (Big Green Book because it is big and green). You can download the bgb online here
http://www.shinny.co.uk/88aw11.pdf It has a troubleshooting guide and simple pictures for some things so it is a good start