To install a spigot on a rain barrel, drill a hole near the bottom side of the barrel, apply silicon on the inside opening of a spigot, insert it into the hole, seal the hole, and secure the spigot. Drill another hole about 2 inches from the top of the barrel, and attach the second spigot. Be sure to install the second spigot on the opposite side of the first spigot.
Turn a barrel on its side, use a measuring tape to measure 2 inches from the bottom of the barrel, mark the area, and drill the marked area with a 1-inch hole bit. Roll the barrel, measure 2 inches from the top, and drill another hole for the overflow. Use a utility knife to cut off the tip of a silicon tubing, press the tubing to release silicon, and apply it to the inside part of the spigot.
Slip the spigot into the bottom hole, and seal the hole with caulk, taking care not to caulk the opening of the spigot. Clean off extra caulking with a clean cloth. Use a wrench and a locking nut to fasten the spigot to the barrel. Be sure to cover the threads with cloth before tightening the nut.
Apply silicon to the inside part of a different spigot, slide the spigot into the top hole, and seal the hole with caulk. Secure the spigot to the barrel with a wrench, and put back the barrel in its place.