Right thepirateway is a good way to do it. Simply drag the .esm and .bsa files into your Data folder that is located in your skyrim folder.
It should look like this: C:\Program Files (x86)\Steam\steamapps\common\Skyrim\Data -> Dawnguard (esm,bsa) Dragonborn (esm,bsa) and HearthFires (esm,bsa) files and make sure to enable the DLCs in your launcher/mod manager
The DLCs are english-only.
I hope I could help you,
best regards