Open it along the seam. (With a sharp knife, but carefully)
Remove the four screws and the contact board. (Don't throw away the screws, we still need them)
Take the WLED controller, remove the connection plug and the white sheathing. Carefully open the cover for the next step.
Remove the remaining white sheathed cables
Carefully pull off the white rest without damaging the other cables.
Cut the cables to a suitable length so that they fit into the housing. Desolder the contact board from the original controller and solder it 1:1 to the new WLED controller with the same orientation.
Insert the WLED controller into the housing.
Insert the contact board into the housing.
Take the back cover and close it with the four screws. 😉
Glue a suitable piece of double-sided adhesive tape to the back of the button.
Fasten it in the middle.
Adopt my configuration⬇️.
Go too Config → LED Preferences → Maximum PSU Current: too
3000
mA
Under:
Hardware setup →
LED outputs:
LED Typ: WS281x
mA/LED: 30mA (typ. 12V)
Length: Long segments have 5 ledes the small ones 1 one. Add them all together and enter the result.