Remove old channels

As a result of trying a number of options to get the RFXCOM binding working working I have managed to create three extra channels to my item that I now want to delete.

The binding is now working but I am getting errors with respect to the other channels that were created while as I was experimenting…

The error message is as follows:

Is there an easy way to get rid of these channels?

This problem seems to have resolved itself after a restart of openHAB 2