Renew NIS 2011 with NIS 2012 using a disc versio

Hi am asking for some advice please.

 

I have NIS 2011 - will expire in about a week. I purchased this through the Norton website but for 2012 the NIS 2012 on a disc was a lot cheaper than renewing.

 

Please can you tell me if & how I should uninstall NIS 2011 before installing the disc for NIS 2012 ?

 

Do I just use the uninstall download tool and follow the instructions, then load in the NIS 2012 disc ?

 

Thanks in advance