I was lucky…the ESP8266 arrived today and I was able to load the firmware. Once loaded, I’ve seen that it behaves like a hotspot.
So I’ve connected to it and by using the IP 192.168.4.1 I’ve been able to log in and setup the home wifi…now I am in…!!! (The IP I’ve took it from a video).
How will I change later on the wifi??? I’ve seen any possibility…so I wouldn’t like to spend time and time configuring something that it will not go in that wifi.
Ok…so I need not just the ESP8266 but also the controller that I still dont’ have 
I have found the solution here: Reset Wifi
Br,
Francesc.