Moving Norton 360 subscription to replacement laptop

I have a Norton 360 subscription that is up for renewal in Oct 2014.

 

I am licensed for 3 installs and have no available installs remaining.

 

I currently have it install on a desktop PC and a laptop.

 

I am replacing the laptop and want to move the subscription to the new laptop.

 

Do I have to purchase a new product key ?   It says it is good for 1 year on 3 PC's.

 

How does this impact my upcoming renewal ?

 

I'm confused about how to handle this. If someone could provide some advice, it would be greatly appreciated.

 

Thank you.