Just drag and drop into your data folder. If you use a mod manager make sure this runs after (overrides) Fellout. I'm pretty sure you could use this standalone but download Fellout and support the original creator!

This is an optional add on for the Point Lookout DLC if you find Fellout to be too dark there too. Either drag and drop into your data folder or try your luck with a mod manager (making sure that this overrides the original Fellout Point Lookout esp)