This is the outside roll, meaning the beads roll towards the outside (away from you). The easiest way to do it is to grip a bead with the thumb and middle finger, so that you can point your index finger straight out. Then, swing the other bead upwards and over your index finger. Once the string starts to wrap around, release the bead you're holding, and it should follow behind the first one. You need a fair bit of momentum for the beads to make it around, so start the trick with a bit of speed