No need to revoke anything; just uninstall Office on the defective laptop. You may have to re-register and activate over the phone, but as long as each license is only actively used on a single computer at any given time, Microsoft doesn't care about your install history (that is, unless it's an OEM license tied to a specific machine, which doesn't appear to be the case).
Edit: I had read somewhere that Office 2007 didn't need activation, but this support page states otherwise. However, you should still be fine with just uninstalling Office from your defective laptop and re-activating/registering it on the new one. You may need to use the phone-in method, but it should still work fine (unless you're unlucky and end up getting shafted by OGA down the road).
But hey, there's always LibreOffice/OpenOffice if your product key gets rejected or you don't want to deal with the hassle of Microsoft's DRM/spyware.