SOLVED Delete - Uninstall - disable language

I downloaded the language pack for my site that I'm setting up but now I find that while configuring the store it would be best to keep the admin in English for the moment as it's easier to search the documentation and forums etc for help. I don't want to put all of Joomla admin in English as my client uses it and would be completely lost as he does not understand.
How can I disable or unistall the language?

Many thanks

DOH! I had forgotton that in Joomer users config you can set the backend language for a user!
So this is solved.