You can change the status of a Checked in source code control file so you can modify it, but after modification, you will not be able to check it back into the source code control database. This feature is provided to allow you to experiment with a file by temporarily making it writable. If the revision control database allowed you to override permissions on files without consequence, it would not be providing any valuable control services for you.

Windows	Right-click on the file in Explorer, then click Properties. In the window see if the Locked attribute is checked. If you uncheck it, the file can then be edited.
Mac OS	Choose Make Writable from the VCS Pop-up menu in the editor window (Figure 16.8). You can now modify the file, but you won't be able to check it back into its source code control database.