Product Activation NIS 2011

Hello,

 

I have a three user licence NIS 2011.

It is installed on two PC so I have one activation left.

I will be building another PC soon to replace one of the two Pc's that has NIS installed.

 

How do I claim back one of the activations as the new PC will be a replacement for one of the other two and I will be installing NIS 2011 on it. 

 

Thank you for any advice.

 

Connie