WoWInterface - Problem with loading this tiny UI mod & more

Problem
Well, I've recently started to try to modify some minor stuff in WoW. I like mods like Gypsy where it doesn't completely change the UI and still stays easy on the eyes and easy to understand. So Ive been trying to make some stuff myself, but I have a problem with how to load a mod.

So, I am wishing to, first, do something small like remove the eagles on the WoW GUI. I will use this .lua file "SourceUI-Eagles.lua":

Code:

function sHideEagles()

        MainMenuBarLeftEndCap:Hide()

        MainMenuBarRightEndCap:Hide()

end

Now could someone help me on how to load this using this same .lua file or even a different one? Thank you ahead of time.

More
I saw this MainMenuBarLeftEndCap in another mod. Could someone also tell me where these are all listed? If there is a list or some source for knowing what everything's called. Again, thanks ahead of time.

**Edit: Sorry, can you move this. I posted this in the completely wrong section.**