[ubuntu] How do I change upper case password to lower case?

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http://ubuntuforums.org – When I very recently installed Ubuntu I accidently entered my password in upper case. I tried to change it in 'User Accounts', but I get a message saying the new password is too similar to the old one. If I change it to something very different can I then go back to my preferred password? Or Is there a way of changing my password without using the 'User Accounts'? Thanks Greg (Hardware)