George --
The Enterprise Global file is your organization's "library" of custom Views,
Tables, Filters, Groups, Fields, Reports, etc. It does not and should not
contain tasks or resources. When each PM launches Microsoft Project
Professional and logs into Project Server, he/she will get the latest verson
of every custom object in the Enterprise Global file, including Views,
Tables, Filters, Groups, Fields, Reports, etc. Therefore, there is nothing
you need to do to to update their projects.
On the other hand, if you are NOT talking about the Enterprise Global file,
and instead are referring to an enterprise project template from which your
PM's created their projects, then there is nothing you can do to update
those old projects. Each PM would need to change the projects manually.
Hope this helps.