Hi,
Sorry its taken so long to reply, end of the year assignments due soon and other things need doing...
But anyway, I have never been able to get the corsix mod tools to work myself, I always use the official mod tools from Relic, you can get them here:
LinkWarning though, these take ages to load everything.
Did you get the rar files to extract?
After they are extracted, you will see 8 folders, each has a name relating to what race they are for. You are asking about the Terminators so you want the
adeptus_marines_v1.0, go into this folder and you will see a folder called
attrib.
Now you copy that folder, next go into where you have Dark Crusade installed, by default it should be something like C:\Program Files\THQ\Dawn of War - Dark Crusade and you will see a folder called DXP2. Go into the DXP2 folder and there is a folder called Data, right-click on the Data folder and select paste so the attrib folder will be placed inside.
All that is left, close all windows you have open and start Dark Crusade, while playing you will find a few things have changed, like you can build more then 1 Terminator squad.
This is the way the Adeptus Collection mod works, you don't select it through the games mod manager, it always active, to deactivate it, just remove the attrib folder that you pasted into the DXP2\Data folder.
Hope all that makes sense and helps...