Reset Homey Pro

I don´t understand how to make a factory reset on my homey pro. I tried to do it as you have written, from my computer but can´t get it to contact the device, somwhere I read you can only control the device by a smartphone.
Now I have been fooling around and my smartphone (android) can´t even find the WIFI from the homey, can´t do anything anymore.

How do I do a real factory reset in my situation?

Did you try to hold your homey upside down. After a few seconds you will hear homey counting down from 10 till zero.