Turn the knob to Battery Test. The needle should be on or to the right of the diagonal line marked "Batt Test" on the meter scale. If the needle reads left of the line, replace the battery by unscrewing the four back screws. A regular 9-volt battery will last for about 10 hours of testing: an alkaline will last for 50 hours.

2.  Set the meter on Sum

On SUM, the meter will add any changes in the electric field to any changes in the magnetic field, so that if either field increases or decreases, the needle will rise above zero.  Anything above zero is significant.

3.  Set the tone threshold

The side knob controls the tone threshold. The tone sounds only if the needle deflection is sufficiently high. The tone won't sound at all if the knob is turned all the way counterclockwise.

4.  Place the meter upright on a stationary metal surface.

If a metal surface is not available just remember to put the meter down.  You will see in Ghost Hunting shows people walking around with the meter in their hands.  This looks cool for TV but will not give accurate readings.