Unlocker
Unlocker can delete any type of locked files or directories (when access is denied).
How to use it ?
Solution 1 : make a shortcut of UnlockerLKL.exe file on your desktop and drop on the shortcut all files or directories to unlock.
Solution 2 : enable KeyFilesAssoc (LiberKey Tools -> Enable file associations). So, a right click on a file or directory allows you to select Unlocker.