[BK7231N] How to flash Gembird TSL-PS-S4U-01-W CB2S power strip

BK7231N, Gembird TSL-PS-S4U-01-W power strip

There are 8 screws at the bottom side under rubber feet.
The screws are "slotted screws with split groove" and you need a special (U-formed) screwdriver (picture 1).
The bottom circuit board (picture 2) is not that difficult to remove (using a decent solder station).
Remove the power cord (A) and then desolder the grounding points (B).
After this, the board is easy to remove and the the CB2S is easy to desolder.
And after this, reprogram the CB2S module as described here: https://www.elektroda.com/news/news3951016.html
I have chosen to have the four power outlets as power1 - power4, and the USB outlets as power5.