Renewal - do I have to re-install in this case?

I have NIS 2012 installed on our 3 PCs.  The service is expiring soon.

 

Rather than renew online, I bought a retail copy of the product at Staples, on sale.  

 

Do I have to remove the current installation and install the new one to activate this product, or can I just enter the new product code/key into the current install?  Thanks,

 

 

Win7x64 SP1 - NIS 2012