These are the steps to update existing Entourage 2008 clients to the Web Services Edition.
Step 1 : Make sure that the existing version of Entourage is version 12.2.9. You can install Office 2008 updates by clicking on the Help > Check for Updates menu, in Entourage. Then use the Microsoft AutoUpdate utility to download the latest updates, to bring the version to 12.2.9.
Step 2 : Download the Entourage 2008 Web Services Edition from http://www.microsoft.com/mac/downloads . This is found under the Office 2008 downloads section.
Step 3 : Quit Safari and Office applications and run the update installer. After installing the Web Services Edition, launch Entourage and in the Setup Assistance, choose ‘Import from a previous version of Entourage’. In the next screen select the version as ‘Entourage 2008’. Select all the mail items when importing information. This will import information stored in the local folders, under ‘On My Computer’.
Step 4 : If an Exchange account is imported, you will need to modify the Exchange Server settings, in the Account Settings of Entourage 2008.