For this achievement you will need to collect all CD-DVDs from the missions on Act 2 and Communiti.
Here are 2 guides that help me find them.
You don't need to finish the mission, grab them an leave mission.
Act 2 -
https://steamcommunity.com/sharedfiles/filedetails/?id=36929...Communiti -
https://steamcommunity.com/sharedfiles/filedetails/?id=35951...