Did this with an old BT Home Hub 2 ages ago to extend my WiFi to the workshop. Darned if I can remember why as I had run a cat 5 cable when I built the place. Also used a Hub 5 a couple of years ago to get good WiFi to the guest room.
Both work well but the Hub 5 has a permanent warning light on so its not completely happy about something.
I had to find detailed instructions on the internet as the procedure isn't quite generic and BT hubs are a bit different when it comes to setting up. Other makes may also have thier little quirks. I'm told that BT Hub 6 (and presumably later models) don't play well at this due to set up issues. Do-able I believe but others are easier.
Clive