Don't drop the tank! Your just making work for yourself. The hole through which you have to clean the tank is the same size weather you drop the tank or not. Remove the fuel pump and boot and the fuel sending unit. Siphon out everything you can and wipe the rest out with rags. Get some Gunk engine degreaser and spray the entire inside of the tank. Scrub it out with a long handled toilet brush. Work around the baffles and wire retainers. Hose the inside down with your garden hose and then vacuum it out with a wet dry shop vac. Repeat as many times as in necessary. When clean, wipe it our with a clean towel and let ir dry for a few days before you reassemble and fill it with fuel. A simple $9.00 flourescent work light from WalMart fits right into the sending unit hole so you can see how you're doing, but make sure you only use the light after your first flush with the hose. Jim