How do I edit what skills a class can have in Wotlk?

[Anime50]

I saw stoneharry do this when he attempted making a custom class, where he added a bunch of skills for a new class. I want to do something simpler, where I simply add skills to an existing class. For example, I want to add the Sword skill to Priests. How would I do that?

I know from stoneharry's ventures, that I most likely edit the SkillRaceClassInfo.dbc and add classmasks to certain values, and export and import with their SpellEditor program, since that's what they seem to have done? (I'm not too sure), but I don't know what exact values to edit as there seems to be a lot for the Sword ID and after poking around and adding the Priest classmask number to various things, all I managed to achieve was a visual glitch in the Skills tab, where Priest now have companions as a skill and the mace and daggers skills are gone lol (although still equipable!).

Does anyone know how to do this? I just want to add weapon and armors skills to a bunch of classes so I can mess around in my own pserver.