Do you mean you downloaded a lockscreen from google play? Or you put a password on you phone and you cant unlock it? If you downloaded a lockscreen from google play, the simply uninstall the app or if there is an option inside of the app to turn it off, then tap that. If you put a password on your phone and you cant get back into it, then you cant really do anything. Well at least of what I know. I cant help you with that part of the problem (if that is the problem).
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