Yoko-otoshi
(side drop)

"From a right handed grip break Uke's balance to his left while moving your right foot slightly to the right. This will force Uke to take most of the weight on to his right foot to regain his balance.
As he does this immediately break his balance to his right. Place your left calf on Uke's right ankle and drop to your left side and pull Uke to your left with both hands. This will cause Uke to be thrown.