Please check the below document which shows the clear steps on how to unlock the page(locking will prevent you from editing the content on page). Also it details about how to cancel the inheritence incase if your component is inherited if you are unable to edit.
The "admin" account can unlock any page by opening the page and clicking on "Unlock Page" from the page properties drop down
NOTE: The original user holding the lock does have permission to unlock the page. However, other users, even if a member of the administrators group, DO NOT have the right to unlock pages that have been locked. Only the "admin" account has this right.