Determine the location of the solar light. Most solar lights must receive direct sunlight for several hours during the day to charge.
If the light has a ground spike and stake, push the ground spike into the ground firmly. Attach the light stake to the spike and the solar light to the stake. If the light merely rests on the ground, make sure that the surface is stable, and place the light.
Allow the solar light to charge for a few hours. Turn on the light and the automatic on/off switch.
Test the light by covering it to simulate darkness or check that it is working at night.
Turn the solar light off. Remove the screws holding the battery cover on the light.
Remove the battery cover and old batteries.
Replace the batteries with new ones and reinstall the battery cover and screws.
Return the light to its stake or previous position, and turn the light back on.