LarkBox Pro - CMOS Battery drained

After 2 years and 3 months the CMOS battery is sucessfully dead. The mini PC doesn’t save any BIOS change anymore, and auto powers on after i plug it (powers on, powers off, then powers on again). Can someone instruct me on how to replace it? Thanks

Write to Service@chuwi.com and ask if we have still some stock but i doubt as its a quite old product