If you have the ability to get under the car and have the tools to remove and fit the exhaust then it can be done and some members have down it on here. Although I would always recommend getting a garage to fit it for you, it will more than likely save you time and you can be sure it's all fitted correctly.
The Invidia is a true dual exhaust because it uses an X pipe creating a dual pipe throughout, rather than a Y pipe which goes into one centre pipe, then into the rear back rear silencer. Having twin pipes throughout makes a true dual system the buddy club only consists of a Y pipe, one centre pipe and dual silencers.
A true dual is supposed to give more power gains as the flow is less restricted with the X pipe compared to the Y.
Have you heard the buddy club? It's very loud!