These lighting units are usually self-contained. They have a small solar panel that converts sunlight to electricity. The electricity is stored in a small battery and used to power the unit at night.
Outdoor solar powered lights usually require between 4 and 8 hours of sunlight to fully charge their batteries. Check to see if the batteries are removable (this will save you having to buy a new unit if the battery dies).
Otherwise let your imagination run wild and try to think of some new ways to take advantage of solar lighting.