Connecting an AirPort Extreme

[#1]

My Technicolor router died, so suddenly no internet. Fortunately, I had a spare that worked, apart from wifi, meaning that it was fine for anything connected via Ethernet. I was able to connect my AirPort Extreme ( in another room) via the existing cabling and that works fine, apart from reduced strength at the other end of the house. I've now moved the AE and connected it to the technicolor (the one with no wifi) and all works well. However, I can't successfully connect it directly to the Openreach modem. I thought I would be able to replace the technicolor router with the AE. Any thoughts on what I'm doing wrong?

[#2]

You need to connect to the AE with the Airport utility to change the settings

[#3]

Thanks, zpeterk. I have the AirPort Utility on my iPad, but that doesn't seem to have any way of altering settings. Maybe I need to get to it via my ancient laptop (which is very slow and use rarely!) Do you have any more detailed suggestions. As you can probably guess, I'm not very savvy at this sort of stuff!

[#4]

@Col - From the AirPort utility tap the AirPort Time Capsule image this will display a dialog box with an edit link (top right) and from there you can make the required changes via the appropriate options.