How do I change a unit?

RedHeavenHero, thank you very much, but what does everything here mean?)
And is it possible to do this for a specific creature?

The values within the HeroDamageLevel1 tags represent the number of creatures a hero kills upon attack if the hero is level one. Each item corresponds to the creature's level, and the number inside indicates the number of creatures killed. The same applies to HeroDamageLevel30, but there the hero is level thirty. All intermediate levels are calculated based on the first and thirtieth levels.