The Best way to install the Extra DVD is either after downloading or after coping the 'ExtrasData' folder off the disk place the folder somewhere your computer can use. Then in the software go to Tools > Options > Folder > in the drop down menu pick "library .lbr" you will see paths to the libraries you use. Click on add then the 3 dots next to the new text box. Then find the path to your folder like :/folder/ExtrasData/Library/ and hit ok and restart the software.

This link may also help:

http://www.hash.com/lib