Update file locking docs

- Remove outdated 'introduced in' section
- Update/remove images

doc/user/project/file_lock.md

 # File Locking **[PREMIUM]**
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/440) in [GitLab Premium](https://about.gitlab.com/pricing/) 8.9.
-> - This feature needs to have a license with the "File Lock" option enabled.
-> - If you are using Premium but you don't see the "Lock" button, ask your GitLab administrator.
+> [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/440) in [GitLab Premium](https://about.gitlab.com/pricing/) 8.9.
 
 File Locking helps you avoid merge conflicts and better manage your binary files.
 Lock any file or directory, make your changes, and then unlock it so another
@@ -30,12 +28,51 @@ The file locking feature is useful in situations when:
 Locked directories are locked recursively, which means that everything that
 lies under them is also locked.
 
+## Locking a file or a directory
+
+NOTE: **Note:**
+Locking only works for the default branch you have set in the project's settings
+(usually `master`).
+
+To lock a file:
+
+1. Navigate to your project's **Repository > Files**.
+1. Pick the file you want to lock.
+1. Click the "Lock" button.
+
+    ![Locking file](img/file_lock.png)
+
+To lock an entire directory, look for the "Lock" link next to "History".
+
+After you lock a file or directory, it will appear as locked in the repository
+view.
+
+![Repository view](img/file_lock_repository_view.png)
+
+Once locked, any merge request to the default branch will fail
+to merge until the file becomes unlocked.
+
+## Unlocking a file or a directory
+
+To unlock a file or a directory, follow the same procedure as when you locked
+them. For a detailed view of every existing lock, see the next section on
+"Viewing and managing existing locks".
+
+You can unlock a file that yourself or someone else previously locked as long
+as you have Maintainer or above [permissions](../permissions.md) to the project.
+
+## Viewing and managing existing locks
+
+To view or manage every existing lock, navigate to the
+**Project > Repository > Locked Files** area. There, you can view all existing
+locks and [remove the ones you have permission for](#permissions-on-file-locking).
+
 ## Permissions on file locking
 
 The user that locks a file or directory **is the only one** that can edit and
 push their changes back to the repository where the locked objects are located.
 
-Locks can be created by any person who has [push access](../../user/permissions.md) to the repository; i.e.,
+Locks can be created by any person who has [push access](../permissions.md) to the repository; i.e.,
 Developer and higher level, and can be removed solely by their author and any
 user with Maintainer permissions and above.
 
@@ -61,41 +98,3 @@ accepts a merge request, an error message will appear stating that the file
 is locked.
 
 ![Merge request error message](img/file_lock_merge_request_error_message.png)
-
-## Locking a file or a directory
-
->**Note:**
-Locking only works for the default branch you have set in the project's settings
-(usually `master`).
-
-To lock a file, navigate to the repository tree under the **Repository > Files** tab,
-pick the file you want to lock and hit the "Lock" button.
-
-![Locking file](img/file_lock.png)
-
----
-
-To lock an entire directory, look for the "Lock" link next to "History".
-
-![Locking directory](img/file_lock_folders.png)
-
----
-
-After you lock a file or directory, it will appear as locked in the repository
-view.
-
-![Repository view](img/file_lock_repository_view.png)
-
-## Unlocking a file or a directory
-
-To unlock a file or a directory, follow the same procedure as when you locked
-them. For a detailed view of every existing lock, see the next section on
-"Viewing and managing existing locks".
-
-## Viewing and managing existing locks
-
-To view or manage every existing lock, navigate to the
-**Project > Repository > Locked Files** area. There, you can view all existing
-locks and [remove the ones you have permission for](#permissions-on-file-locking).
-
-![Locked Files](img/file_lock_list.png)