Reassigning license for Office 2007 Home and Student

I have the above software now installed on three computers as per the license agreement from Microsoft. Unfortunately, the new computer is defective and must go back to the store. I know from the MS site that I have to "reassign" the license to the new computer, but nowhere can I find out HOW to do this? Does the installation disk automatically ask this if I try to install over the 3 computer limit?? Just want to know this before we box up the computer.

 

You may have to call Microsoft to activate over the phone and explain what happened.