Step by step you first install NR2003 of course.
Then you install the patch to upgrade to the latest version using this file:
002_NR_1201_Update.exeThen you download NR2003_noCD.rar, unzip it with Winrar or 7zip, move the nr2003.exe into your \Papyrus\NASCAR Racing 2003 Season folder.
Then you do the core.ini change as described
here.Then you install the
MENCup18 mod. Simply extract the zip container into your
\Papyrus\NASCAR Racing 2003 Season\series directory
Then you install the
update for the mod. Simply extract, then copy the included
MENCup2018.dat and paste it into your
\Papyrus\NASCAR Racing 2003 Season\series\MENCup2018 directory.
Then you download all the
carfiles and move those to your
\Papyrus\NASCAR Racing 2003 Season\series\MENCup2018\cars directory.
Now you are ready to race online again.
[Most those other files from the link you posted are for other mods such as the PWF Busch Series, TransAm and Truck expansions and the in-game cup mod, so you do not need them, unless you race offline against the computer a lot like I do.]