At a mcdonald's, I pee'd into a condom for my friend and he taped it to his leg and just punctured it into the cup.
The other method is too just drink tons of water, you're urine becomes so diluted (clear in color) that it's nearly untraceable. You'll have to drink an exorbitant amount though, timing will be difficult.
Anyway, never had to deal with this issue on a personal level, but know from associates that this is the way to go.
My friend passed his drug test btw with the condom.
