Your Dark Souls 2 files need to be extracted and your .exe needs to be patched to load loose files. TKGP's UXM accomplishes both of these things: https://www.nexusmods.com/sekiro/mods/26 (Although UXM is in the Sekiro nexus, it works for all Souls games)
To install, place the "param" folder in your Dark Souls 2 directory. Be sure to make a backup of your original "param" folder before you add the mod to it.
This mod is not compatible with online play, and as with any mod you run the risk of being banned if you go online with it. I highly recommend playing offline while using this mod, then restoring your param folder with a backup when you have cleared Brightstone Cove, which is the level this mod edits.