Flower Gardener wrote:

I need to change one field to another value for a large number of
contacts in my file. Is there any way to do this with a single
operation rather than opening each contact and making the change?

Depends on the field whether or not you can do it without buying a
third-party tool, but since you give no details, that's the best I can do.
--
Brian Tillman [MVP-Outlook]