As chmee said the lua files are normal text files so you can edit them with something as simple as notepad.
The tooltips for the buffs and debuffs were turned off as it would cause problems for click attackers. But the setting is overridable by enabling interactivity of the aura buttons.
Folder: Interface\AddOns\nUI\Layouts\Default\HUDLayouts\PlayerTarget
File: nUI_HUDSkin_PlayerTarget_Player.lua and nUI_HUDSkin_PlayerTarget_Target.lua
PlayerTarget portion is the name of the HUD layout you use so change that accordingly.
In the player file you will see a block like this:
Code:
["Aura"] =
{
[1] = -- debuffs
{
anchor =
{
anchor_pt = "TOPRIGHT",
relative_to = "$parent_Health",
relative_pt = "TOPLEFT",
xOfs = 40,
yOfs = -100,
},
options =
{
enabled = true,
size = 45,
strata = nil,
level = 1,
aura_type = "harm",
origin = "TOPRIGHT",
player_auras = false,
dispellable = false,
horizontal = false,
highlight_player = false,
aura_types = true,
cooldown_anim = false,
flash_expire = true,
clickable = false, <<< change to true
rows = 3,
cols = 4,
expire_time = 10,
hGap = 5,
vGap = 20,
The target file will have something similar.
I believe that will make it so that on mouseover tooltips will appear. If memory serves me right.