How can I clear thc out of my system?

I hardly ever smoke, maybe once every couple of months (if even). I had one hit a few nights ago, and now have to undergo a drug screen at any time without a lot of notice. I drink 2-3 cups of tea every day ( I don't like coffee). What do I need to do to ensure there is no THC in my system quickly?

just keep drinkin that tea (hopefully its green tea, it works best) and lots of it! Also take Niacin wit it.. you will p*ss the THC outta ya!