dbc character swap?

[Android14]

I am aware of normal modeling swapping with .m2 files and switching around .blp files, but how would i go about swapping pre existing dbc characters like in this video?

I imagine it is just some number editing in dbc files but im not sure where to start.
I want to swap the tauren and taunkas, and had a project like this back mists, but it was a mess swapping so many face files around and dealing with baked npc textures, so I just gave up.

EDIT: After talking to MR.GM, he said he edited the database? Not sure what this means, but my question still remains, what would be the easiest way to swap tauren to taunka?