While Dark Souls has always had optimization issues, it runs particularly bad on PC compared to consoles. The upside to the Mod Manager though is that it makes it much easier to remove mods that aren't working right or causing problems in the game without having to remove them manually. All players really need to do is download the files and then extract them into whatever folder the DarkSouls.exe file is.
Almost all mods on Nexus Mods will come with instructions for installing them, and even if they don't it's pretty easy. Those who don't want to use the Mod Manager, or can't get it to work for some reason still have options though. They then just need to open the Mod Manager and any downloaded mods can be dragged right into the Mod Manager interface. Players who download Drag and Drop Mod Manager will need to move the downloaded files straight into their Dark Souls file folders. One of the best ones is called Drag and Drop Mod Manager, and it makes the entire process for installing mods incredibly simple.
After that to start downloading mods for Dark Souls, players will want to install a Mod Manager before they do anything else.