Help Installing Mods

[Der Landser]

I'd like to install the Long War Mod for SAW, but I have a few questions regarding how to install the mod.

I've read other threads that recommend installing mods into a separate folder for that mod. I assume the reason is to keep the original game folder stock and intact and to provide a separate folder for the mod in the event the mod modifies files that are common to both the original game and the mod.

I've also read that the new folder for the mod can either be created by installing a second instance of the original game under a different folder name or by simply copying the original game folder and renaming it.

So, bearing in mind that I don't have an issue with creating a second installation from scratch, is it advisable to install the mod to the original game folder or is it best to install the mod to a separate folder? What method should I use to create the new folder for the mod which will result in a trouble and bug free installation? Should I copy the original game folder and rename it or perform a second installation?