Determine a safe area to discharge the water. This area should be lower than the bottom of the gutter downspout so that the water is able to drain there easily.
Dig a hole under the gutter downspout large enough to bury the catch basin and insert the basin into the hole. Skip this step if you are not installing a catch basin.
Dig a trench wide enough and deep enough to hold the drainage pipe from the bottom of the gutter downspout (or catch basin) to the safe discharge area. Begin the trench directly under the downspout (or at the catch basin) and continue it to the safe discharge area you have chosen.
Lay the drainage pipe into the trench. (Attach it to the catch basin with PVC cement, if you are installing a catch basin.) If jointing the pipe, use PVC cement to attach or follow the manufacturer's instructions.
At the end of the pipe in the safe drainage area, attach the pop up emitter according to the package instructions. The top of the pop up emitter should be slightly above ground level.
Cover the catch basin and drainage pipe with dirt. Leave the top of the pop up emitter above ground, according to package instructions.