Norton Internet Security 2008 - 2009

Hi, I have Norton Internet Security 2008 installed on my PC, I have a matter of days left on my subscription. Yesterday I purchased a licence of Norton Internet Security 2009 from a dealer thinking I can renew my subscription with Norton 2008. No the key is too long so I am at a bit of a loose end just now. I dont know if I have to uninstall 2008 download a new version (2009) from the Norton site before I can activate my new key???