First you have to do is to visualize any negativity that you want to get rid off. Visualize putting that negativity to a box or chest and sealing it. Then find a shadow, prefered is some large one. Visualize it slowly starting to move and creating a whirlwind of shadows.Visualize taking that box/chest and throwing it to the shadow whirlwind. Then do the chant. Chant:
Shadows I ask of thee To take this negativity of me To make me free So mote it be.
Then visualize how the shadows slowly stop moving and returning to previous state.