Converting from trial to full version Endnote X2

I have been using a trial version of Endnote X2, which will soon expire.  I also recently purchased a full copy, but I have had trouble installing that.  The install disk gives me three install options, none of which seem to correspond to "replacing trial version with full version).  I used the “modify” option, and the disk spent some time running through install procedures, but when I restarted Endnote, I still got the “trial version will expire in X days” message.

What install should I have chosen?  Do I need to uninstall the trial version first?  If so, what will happen to the libraries that I created with the trial version?

I am running on Windows Vista.

I always uninstall the previous version before installing a new version. It will not delete the libraries and it usually retains any customized settings you may have made.