As per Keith's post above, you should be able to use http://mybtdevice.home to access the Extender’s settings.
Alternatively, if you know the device's IP address then you can also enter that directly (e.g. http://192.168.1.123).
If you don't know you Extender's IP address, you can locate this from your Hub/Router's settings. The BT Extender will be identifiable by the device/hostname – for the BT Wi-Fi Extender 610, this will be “BT-DualBand-WiFi-Extender”.
Thanks to you both but the http://mybtdevice.home page doesn't load for me at all.
The IP address of my wifi extender is supposed to be 192.168.1.1 and that page cannot be reached. That's why I asked this question in the first place. I don't understand why neither will work for me.
Keith, I solved the previous problem by changing the SSID using the above IP address. The answers received confused me further!
Unless you have given the extender a static IP address of 192.168.1.1, it will be allocated one by the Hub's DHCP server. If you go 'My Devices' in your Home Hub you should be able to see the device and its IP address listed there.
It might be worth factory resetting the extender.
The IP address of 192.168.1.1 is only used whilst the device has not been configured. Were you connected to the Wi-Fi extender when trying http://mybtdevice.home URL?
Once the device has been setup it will obtain its IP address from the router/Hub.
What is the current range LED showing on the Extender (Too close, Good range, Too far)?