The exact charger you have will vary but the one you have should look a bit like this one.
To charge the battery find an adapter and plug the charger into the mains, all three LED's should light up red. Take the battery and placing it in the lipo-safe bag so that only the leads protrude then take the four pin lead from the battery and plug that into the four pin connector on the charger noting the direction they are keyed in.
Always make sure that you charge the battery in a lipo-safe bag. If you have any reason to suspect that the battery is damaged do **NOT** use it.
When the battery is charged all 3 LED's will turn green, if the LED's flash red it means that there is a problem with your battery and you should contact us immediately.