Resolution
The Project Server administrator should complete the following steps:
1. Launch Microsoft Project Professional and log into Project Server with administrator permissions
2. Open a new blank project
3. Click View - Resource Sheet
4. Type the name of the resource whose user account you want to convert
5. Click File - Save and then click the Save as File button
6. Save the blank project as an .mpp file with a name like "Resources to Import.mpp"
7. Close the project containing the resource
8. Click Tools - Enterprise Options - Import Resources to Enterprise
9. In the Import Resources to Enterprise dialog, select the .mpp file containing the new resource
10. In the Import Resources to Enterprise dialog, map the resource in the .mpp file to the user account in Project Web Access and then import the resource
11. Click Tools - Enterprise Options - Open Enterprise Resource Pool and check out the newly-imported resource
12. Set values for all default and enterprise custom fields for this new resource
13. Save and close the Enterprise Resource Pool