Installation:
Use a Mod Manager, Vortex | Mod Organizer 2
Sort with LOOT.
Load Order:
HNVMain.esp
Better Vampires.esp
HNV and BV Patch.esp
Recommended patches and fixes:
Vampire Lord Gear Swap: There is a patch provided by phinix to fix the armor swapping, make sure to follow his guide.
Vampire Lord Animations: You know the drill. Humanoid Vampire Lord Bats Power Fix.
Don't forget, both Phinix HVL gear swap fix and Bats Power Fix need to overwrite HVL.