The process should be go to workshop for DoD, find a mod there, click subscribe on it, and when you launch the game in the launcher choose the option to select mods, and put a checkmark next to each you want to use.

I'm currently having a problem where none of them are showing up in my game launcher though, so I'm maybe not the best person to answer this. (See my other post)

They show up for me. Wow, I feel so stupid for not realizing it was that easy...