Find an assistant. You will need someone to stand on stage while you focus your lights to ensure the proper areas are being lit.
If you don't have them already, attach safety clips to all of your lights. These are generally made from flexible metal cables about 12 inches in length and closed with a carabiner. Safety clips can be purchased at theatrical or lighting supply stores.
The cable should pass through the arm of the lamp, and around the pipe or batten the instrument is attached to.
Loosen the light from its current position, using a crescent wrench. Make sure to keep the safety cable attached.
Move the lamp to the correct position, and secure the instrument by tightening the instrument's clamp, using the crescent wrench.
Focus the light by adjusting the angle of the instrument or by adjusting the barn doors on the instrument. Have your assistant stand in place so you can see how the light looks on a human body.
Move the booms, if you are using them. If your lights are attached to booms, they should always have safety cables. In addition, the base of the boom should always be weighed down with sandbags or stage weights.
To move the boom, remove the sandbags. Tilt the boom at a 45 degree angle and roll it into place. Then replace the sandbags. You may need an assistant to help you move a boom.