A weatherproof light is one of the great conveniences of outdoor life, and Eveready's Energizer brand floating lanterns are a durable example of the breed. The relatively bulky 6-volt battery will need to be changed occasionally, but will provide many hours or even days of use once installed. Changing a battery is very simple and takes only seconds, even if you're doing it under poor conditions.
Grasp the body of the light firmly in one hand and hold it upright with the lamp assembly facing up. Grip the black plastic ring surrounding the lens and lamp assembly and turn it counter-clockwise until it comes free from the lamp.
Set the ring on a nearby surface and lift out the lens and lamp assembly. The lens is just a thin piece of plastic and it will blow away easily, so it's best to put it inside the ring and then place the lamp assembly on top. Keeping the assembly together reduces the risk of losing the lens and also protects the LED lamps from water and dirt.
Point the open body of the lantern downward and give it a light shake to slide the old battery from the compartment. Preserve it and dispose of it safely, in accordance with local law.
Remove the packaging from your replacement battery and slide it into the battery compartment, with its springs facing upward.
Locate the fork-shaped metal flange at the bottom of the lamp assembly. Line this up with the ridge of plastic you'll see inside the lantern's body, opposite the switch for the lamp. Drop the lamp assembly into place and position the lens and ring on top of it.
Screw the ring clockwise, until firmly seated, to re-seal the battery compartment. Press the on-off switch to test the light and to make sure that it's working properly.