Editing unit abilities

[dmolnar]

Hello
I'm kinda "old" with Majesty, but now I want to get familiar with modding and editing the game. My two questions are:
- Can an already existing spell added to a hero who has no spells? If yes, how? (Like adding "Damage shield" for Warriors, for example)
- Can armor types edited? For example changing a "Chain mail" to "Leather armor", or "No armor" to something.?
Thanks for the help.

[dmolnar]

One more thing: I edited some data in the respected files at the game library. However, when I'm launch the game, these don't take any effect, like I modified nothing at all.