If you haven’t done so, install your original game and remember the target installation directory as you need some game files later

Browse to the iortcw project release folder https://github.com/iortcw/iortcw/releases and grap the latest release files for your operating system. At the point of writing the latest version was v1.51b.

Also grap the latest patch file from this site: This was this file as per now patch-data-141.zip

Extract the latest release zip into a location where you like to have your installation going forward (like c:\Games\ioRTCW\ in Windows or /home/joe/Games/ioRTCW/ in Linux

Go to the location of your existing original installation, go into the “Main” folder and copy the following files over to your ioRTCW “main” folder: pak0.pk3, sp_pak1.pk3 sp_pak2.pk3 sp_pak3.pk3. This is the game date for the single player mod.

Then extract the content of patch-data-141.zip (or a newer version in the meantime) into your iortcw folder and merge its content into it

And that should be it actually: Go to your iortcw installation folder and start either the “iowolfsp*” file for single player or “iowolfmp*” for multiplayer.