How to change battery in the SK636 or SK638?
How to change the battery:
1. Unplug the AC adapter from the wall socket and from the light unit.
2. Remove four screws on the back cover and remove the cover.
3. Remove the battery terminals from the battery. Do not touch anything else inside.
4. Insert a flat head screw driver under the battery, slowly ply out the battery from the housing and recycle it properly. The battery is glued to the housing using double sided foam tapes.
5. Reverse the process with new battery.