Remove the power supply, such as batteries or the AC adapter, from the stomp box.
Remove the screws holding the stomp box together with a screwdriver.
Pull off the stomp box's cover.
Pull the circuit out of the stomp box.
Place the tip of a hot soldering iron and desoldering braid on the joint of an electronic component you want to remove.
Remove the soldering iron and desoldering braid from the circuit board when the solder is on the desoldering braid.
Place electronic components in the holes in the circuit board. Use the side of the circuit board that isn't used for soldering.
Flip the circuit board to the soldering side.
Bend the component's leads to secure them. Do not bend pins on microchips.
Place the tip of a hot soldering iron and solder on the copper joint where the component meets the circuit board. Remove the soldering iron and solder from the board when the melted solder has secured the component to the circuit board.
Trim the component's leads with wire clippers.
Strip both ends of a piece of wire with wire strippers until 1/4 inch of wire is exposed. Repeat this process for all of the required wire. For example, if you're adding a single pole single throw (SPST) switch, you need two pieces of stripped wire. If you're adding resistors, capacitors or other through-hole components with long leads, you might not need wire.
Solder one end of the wire to the component you're adding.
Solder the remaining end of the wire to a copper track on the circuit board.
Drill holes into the stomp box if you added external components, such as switches and knobs. Each hole is the same width as the external part of the component. For example, if you added a potentiometer, the width of the hole is equal to the width of the potentiometer's shaft.
Put the circuit board inside the stomp box. Pull external components through the drilled holes, if necessary.
Screw the cover onto the stomp box.