Sit on the edge of your bed. Turn your head 45 degrees to the left (not as far as your left shoulder). Place a pillow under you so when you lie down, it rests between your shoulders rather than under your head.
Quickly lie down on your back, with your head on the bed (still at the 45-degree angle). The pillow should be under your shoulders. Wait 30 seconds (for any vertigo to stop).
Turn your head halfway (90 degrees) to the right without raising it. Wait 30 seconds.