You need to have installed the Stardock Central program.
Once installed open the program and click on the following: -
'Tools' - 'Lookup Serial No' & enter your email you purcased the game with
Go to your email program and open the emial from Stardock.
In the email is the serial number for DA - Copy this.
Go back to SDC (Stardock Central) and click on the 'Games' tab (left)
At the bottom of the screen is a checkbox with 'show pre-release versions' next to it. Ensure this is checked!
Click the '+' symbol next to Galciv 2
At the end of the list you should see the DA link.
Right click the link and select 'register products'
Enter the reg details from the email.
Now you should be able to download the game 
If the DA section does not appear please try the following first: -
Open SDC and go to 'Tools' - 'Settings' - 'internt' and make sure you have 'US-1' as the curent server.
Then click the 'Refresh XML Data' button.
Once this is done you should then see the game listed under the GC2 header.Hope that helps.
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