Hi Guys, I have a PDF file which is available to view. Its file record is locked (shows lock icon). It was created by previous employee who is not with us. How can i change the lock to make the edit in File record ?

It may be locked by workflow, try to find the Workflow applied in the transaction (you can navigate to Customization > Script > Scripted Records) and find the "Lock Record" action. Once you find it, you can just inactivate/remove the action

Is the {DF part of a bundle? It might have been locked when the bundle is created. If that is the case, you will need to edit the original bundle and remove the lock