You don't need to extract them. We simplified the DLC process, so you just put the rpa files into the folder. But if you have older versions that were zips, you should update the base game and those DLC to be the latest versions. The new DLCs can't work with old builds. Removing the old versions won't delete your save files!
Viewing post in Our Life: Beginnings & Always - Derek's Story comments
Ok. Hm The Step 1-3 bonus DLCs had rpa files and folders. I downloaded everything yesterday for the first time so they should all be updated. I never got Dereks ending in Step 4 so idk what happened. I did take him to the dance in Step 2 which someone on reddit said that means the DLC is in just fine.