Microsoft Office Trial Version and Upgrade

Question

Just bought a laptop yesterday that had the Microsoft Office trial version already installed. I bought the Microsoft Office Professional 2007 Upgrade disk. Will the upgrade work or do I need to buy the full version? If the upgrade will work, do I just need to run the disk or do I need to delete the trial version before I install, or, do I just need to put in the liscence number and not have to install anything?!