Can anyone give me a detailed description, or where I can find one, on how to drain the gas out of the carbs?
Thanks

if you look at the side of the carb at the bottom of the float bowl there is a cross head screw.
undo this and the fuel will drain.

Right near that screw there is a fitting to put hose on. Get some hobby fuel line like for a model airplane and attach it to the fitting. Then open that screw up then you can easily drain the fuel into a can so it doesn't run all over the motor.