It's just this one line:
Config::Set('ERROR_LEVEL', E_ALL ^ E_NOTICE ^ E_WARNING);
You can add it wherever, pretty sure it's in there. Do a find for "ERROR_LEVEL
Make sure the /core/cache directory is 777, ignore the warning for now, or in your local.config.php, at the top, change:
Config::Set('ERROR_LEVEL', E_ALL ^ E_NOTICE);
to
Config::Set('ERROR_LEVEL', E_ALL ^ E_NOTICE ^ E_WARNING);
It's in core/templates, that's where all the originals are
I don't have it on-hand.
In the downloads, there's a tool (WinMerge) which you can use to see the differences