If i have allready bought the retaliation pack, and Decimation pack, and i earlyer installed them.
But since i bought a SSD Drive, i unistalled the game and all extras, so i could run it on my SSD insted.
Where can i then download these packs again ?

Uh boy... You should have backed up your DLC's... But, I think you are able to download them again via the store...