An easier way....put the overflow tube from the carb, into the gas can and open the drain, at the bottom of the float bowl. This will also flush all the crap out from the float bowl.

 

Better yet....I would pull the tank off the quad, turn it upside down and dump it out....that way you will get any crud out of the tank along with it! Then rinse the tank with a little gas a couple times while you are at it. I save the waste gas for cleaning parts.

It's easy! Remove the plastic around the tank. The tank has just a couple bolts up front and some straps in back holding it down. Close the fuel valve and remove the fuel tube. Pull the tank off.....

 

Take off the gas cap and flip the quad over. Shake it around real good.

Na, just kidding. Take the guys advice above. Either of those sounds good.