How do I change Faction names?

Any ideas?

Basically, what I want to do is knock back the start date from 1080 to 1066. I'd like to change "Saxons" to "England" and "Normans" to "Normandy," so you can choose to play as either. It should be relatively easy for a human player to conquer England as William the Conquer; conversely an Anglo-Saxon human player should be able to defend themselves, etc.

Which file would this stuff be in?

Finally, how do I change what kind of stuff each faction can build/train? The Saxons (AFAIK) can't train cavalry - but they did have a navy, and thus should be able to build ships.

Thanks!

PS: I'm new here (from the Paradox forums), so sorry if this one's been answered before - I searched for it but the answer was in relation to MTW, not M2TW.