Turn off and unplug the water fountain.
Remove the water and other water features such as pebbles, water plants and decorations.
Trace the electric line or cable underneath or behind the fountain. Some fountains come with wires built-in making them a little difficult to remove. Loosen or disconnect the wire from the pump and cut the wires as close to the electric pump as possible, using a wire cutter.
Remove the old fountain pump by lifting the suction. Disconnect it from the suction hose or tubing. Some fountains come with glued pumps so that they will not move during operation. In this case, use a sharp object or a crowbar to loosen the glue before you lift the pump.
Clean the interior of the fountain and inspect for any leaks or damage.
Place the new pump in the place where the old pump sat. Use a clamp or put a rock to anchor it in place.
Connect the tubing to the pump. Make sure it is free of debris.
Run the pump wire underneath or behind the fountain. Camouflage with rocks and plants to hide it from view. If the solar panel has a long connection cord, put it on any unobstructed location that it can reach.
Fill the fountain with water. Submerge the pump.
Turn on the pump if it has an on/off switch. Some models do not come with an on/off switch and will automatically run once the sun hits the solar panel. Check the water flow and make adjustments as needed.