Don't spike the cup or you might fail. Given your body size and metabolism you should do just fine. Pick up some metamucil and start taking the recommended dosage. This will help to excrete some of the thc metabolites through your colon. Some cardio will also help you to shed some as well. Read the dilution sticky above and practice with it up until test time. Substitute gatorade for water and cut the liquid dosage in half. Your skinny you should be fine.

Remember don't over hydrate yourself... and don't spike the test.