Power off the Jb-199 unit completely and unplug the power cable.
Take the top cover of JB-199 off by removing the 4 screws on each side and 3 screws on the back.
On the mainboard, look for a (Quarter) coin size battery CS2302 and remove it by releasing the lock holding the battery. Do not damage the lock in the process.
Insert a new CR2032 battery.
Power on the JB-199 unit.
Reset the BIOS setting of the mainboard following the instructions below.
How do I reset the mother board of JB-199 after changing battery or after it has reloaded default settings?