X2 is a full install, and is not in any way dependent on the presence of X1 on your system.
So - no need to install X1 first - meaning ff the upgrade to X1 qualifies you to get X2 then you can just go through the process of downloading and installing X2.
I would imagine you have to register X1 though, so that the system knows what you are eligible for and all.
To register X1 without having to do it through the installation process, go to this link and complete and submit the form online:
http://cakewalk.com/Register/default.aspx Hope this answers your questions - please post any further questions and I will try to help,
Bob Bone