The column sizes are the same in some of the WoD DBCs as in MOP so you can copy/paste in some cases.
You don't need to do this for HD textures though. Just extract the appropriate DBCs (like charsections.DBC) from your current client, convert to a format like .csv with DBCUtil, and edit where appropriate.
I've only modded MOP so if you're on Cata or WotLK I can't help further.