You'll need to DEauthorize Waves on the first computer, and install and authorize on the new computer.
First, visit waves.com and click "register and authorize". At that page, click "access my account". Then download and fill out the reuquest to "Reauthorize", which you'll then need to fax to Waves.

Sspecify on the form that he's removing it from one system and putting it onto another. Further information and instructions will be available at the website.