Thank you for responding.
I just checked the DLC on the store and it is still on sale.
I guess I'll just release my patch along with a few DLC files I've translated or I'll try to make an xdelta patch for them.
(although I'm not sure if this works, because each file DLC only has about 100-200kb, which is really inconvenient for people when patching it manual, I guess I will try making a batch file for it. Hope it will work.)
Btw, thank you for help!