There aren't many free ways to do this.
If you can scroung up some cash, any vitamin store like GNC or something sells clensing kits for 30-50 depending on body size weight and how much clensing. you can ask them for this and they will help you pick one. It does in fact work. A friend used one he is 210lb and 6ft needed to clense weed and coke from his system and he passed his test, you do this the day of or the day before the test, it is just a drink you drink followed by water.
If you can scroung up some cash, any vitamin store like GNC or something sells clensing kits for 30-50 depending on body size weight and how much clensing. you can ask them for this and they will help you pick one. It does in fact work. A friend used one he is 210lb and 6ft needed to clense weed and coke from his system and he passed his test, you do this the day of or the day before the test, it is just a drink you drink followed by water.