How would I go about expanding the Ethiopian units AoR into Ethiopia.

It's pretty well known that a couple Ethiopian units are unrecruitable in Axum. How would I go about getting the AoR for them to include Axum, and maybe Nubia.

There is a mod that accomplishes this objective, but it also adds a few non-ethiopian units into other regionol areas of recruitment. Mostly there is an expansion in factions that can recruit Saba's units through the regional recruitment barracks system, and they also have an expanded AOR for those other factions. In practical terms, this means that Ethiopian swordsman, and their cavalry and Spear counterparts can be trained in Ethiopia by both Saba, and other factions. A few Greek and Eastern units are also affected by this mod. It is located here:
http://www.twcenter.net/forums/showthread.php?t=134817

You can find MiniMe's temporary EDB alteration for 1.1 in the unofficial submods fora - here on this ORG.