I want to change the font of a particular anime series I've acquired, but for the life of me, I cannot figure out how to do it. I've searched Google, but only gotten results from 2010 (where most links are dead and files missing). I've searched the forums. Fansubbing websites. I can't find anything. So I've decided to just ask the community.

For reference, the file is an .mkv, and I assume the fonts are softsubbed.