Your solar flagpole light likely comes in two installation styles — a clamping system or an ornament ball. Thus, your installation process will look different for each of these styles.
A clamp system works by using the included kit pieces to clamp the light and the solar panel to the bottom half of your flagpole. You can usually easily adjust this as needed to achieve the light range and coverage you prefer.
An ornament ball light goes at the very top of your flagpole, rather than towards the bottom. Basically, you simply need to place the solar light on top of your pole and screw the disk into place. Some kits come with the ornament ball, which screws into place on top of the light, while others do not.