Thanks Ruben.
So this is something I need to do manually and then once I've done that I can then run the install which will update the rest of the files automatically, right?
Not if you are UPDATING/UPGRADING your forum vs. INSTALLING the software for the first time or as a fresh/new install.
IF you are upgrading to 7.5.7, for example, from 7.5.6 you would run the "upgrade.php" file via your browser which is typically here:
yourdomain.com/forum/install/upgrade.php