The Ubiquiti products come in a nice solid cardboard box, clear and well packaged. Seeing this appear in front of you is like reliving your package night.
It looks really tight. There is a short instruction and various mounting materials. I myself removed the COAX cable that ran from the meter box to the living room and pulled a (soft core) UTP cable through it. WCD opened and all old-fashioned COAX stuff deposited in the wheelie bin.
What are you left with, an open WCD and a UTP cable, place a connector and connect the Unifi In-Wall HD. Because the mounting plate on the back of the Unifi In-Wall HD has several slots, it fits perfectly on the existing European WCD. A matter of connecting, pressing a few screws and the beautiful cover plate.
Just 'adopt' & update the new equipment in the Unifi Controller (in your browser) and you're good to go! on the entire floor (+/- 50 m2 with a plaster wall here and there) the maximum download speed is achieved which is promised by the telecom provider.