=======================SOLUTION <<<=======================
Well deleting ‘wp-includes/date.php’ didn’t work because the updater needs it!
Same with ‘wp-admin/includes/class-wp-upgrader-skins.php’
However the other 2 files didn’t mind being deleted!
Solution was just to set the Permissions to ‘777’ on both ‘essential files!
Installation went without a hitch!
To make it easier for you don’t go to the bother of backing up and deleting any files, just set Permissions on all of them (the ones mentioned in your failure report) to ‘777’.
No need to reset them to ‘644’ after successful installation, the Installer does it for you.
I set Permissions through the CPanel ‘File Manager’ (last column on the right hand side) but you can use any FTP Program such as ‘FileZilla’ if you are so inclined!
Cheers!