Turn off your Behringer amplifier. Setting up the volume pedal as the master volume can potentially produce sounds that can damage the speakers connected to the amp.
Connect your instrument to the "In" port of the volume pedal using an instrument cable.
Connect the "Out" port of the volume pedal and the "In" port of the amp using an instrument cable.
Turn the master volume dial of the amp to the lowest position.
Push the volume pedal all the way down. This is the position that allows the signal to go through the pedal at full strength.
Turn on the amp.
Adjust the master volume dial to the maximum volume you want to use. This is usually not the same as the maximum setting for this dial.
Push up on the volume pedal to reduce the master volume of the amp. Push down on the pedal to increase the master volume. The entire range of the volume pedal goes from completely muted to the maximum volume you set in Step 7.