Install antivirus to replace trial version of Internet security???

On 7/28/2012 I purchased a new computer with a trial version of Norton internet security preinstalled. The trial period will expire shortly. T the same time I purchased a 3 user Norton antivirus disk which I intend to use instead of extending the internet security. Two questions:

  1.  Must I uninstall Internet security before I install antivirus?
  2. Must I wait until the trial version of internet security expires before I install antivirus?