No problem. This isn't too difficult (excpe part 3).

1. Make a new XML file called MyFaction in the "My Document/Elemental/Races" folder.
2. Copy all the code from the CoreRaces or CoreFactions file
3. Remove all but one faction keeping the first couple lines of code and the last line of code. Those declare and end the document.
4. Customize the faction to your liking
5. Copy the entirety of your sovereigns code into the xml (or keep it separate, your choice)
6. Use your sovereigns Internal Name as the faction's custom or designated leader

The logo will take some more work as it has to be declared in a logo file (see CoreLogo) due to poor mod development organization (bad Stardock!).

It'll be a learning process. Took me a crash or two to figure it out. However, it's worth it and I now have four or five custom factions running around in my game.

NOTE: It is not advisable to edit or change any of the Core files as they will likely be changed and replaced in the event of a patch or update. That will also probably cause problems with multiplayer.

Just attach all the sovereigns code (except maybe the VERY TOP part that looks like administrative code or something) and paste it after your entire faction code.

Like this:

LordaeronRepublic.XML

You can organize it however you want. I use one XML for each race. You can also include all your custom units inside there too if you know what your doing.

Oh crap, its raining outside and I left the sprinkler on... better got stop it. NOOO!