After following several articles:

And failing to make any progress, tried installing with a LAN connection. Kubuntu detected the LAN and used it immediately (no config on my part).

Shortly after the desktop loaded there was a hardware notification for the WifI card, with Kubuntu suggesting two proprietry drivers for download. Chose the one deemed correct and it was downloaded and "installed" - all automatic. No visible problems.

Used the connection manager to see if the WiFi card could detect wireless networks and it did. On trying to connect to the network there was a kernel crash; got a bug report to send in.

The above may or may not work for you, but if after trying all the great documentation and tutorials you are still getting nowhere, try installation with a LAN connection.