Home made changes to the mod

[Allexei]

Say I would like to change which units are recruited where, which buildings do what or what technologies are required for what, how would I proceed? I have been rummaging through the mod files with the pack file manager but a lot of items don't have descriptions so I was hoping someone could tell me what I need to do to make effective changes.

any help would be welcome, cheers.

[Maetharin]

it´s in the DB -> building_units_allowed tables