OP ... I've used it myself (not for translations, but to look at a few things out of curiosity) and the PAK extractor is pretty straight forward. Mind you, some of the PAK files will have a LOT of files inside. So you'll need to do some digging through a bunch of folders.
However, you have my respect for considering tackling a project like translation. Especially a game with as much text as DOS2 has.
If you do decide to do it ... perhaps put up a post listing the language you intend to translate to. I'm sure you'll find others on the forum here who will be glad to pitch in and help.
The only problem would be the SIZE of the translation file and legality of distributing it. But I'm sure if the translation was solid enough you could probably work something out with the company.