Default [Q] How do I remove a problematic lockscreen on MIUI v3?

So I downloaded a lockscreen for MIUI from the themes app but apparently it doesn't go well with my phone and it just displays the wallpaper without the actual lockscreen. The problem is, now, I can't unlock the phone as there is nothing to drag on the screen. My phone is also secured by a pattern. How do I remove this problematic custom lockscreen and revert to the stock one?

Obviously I'd either have to do it via ADB or something. Can anyone help me out? I can restart the phone but that's really all I can do since everything else is behind the lockscreen.