Export and Edit Your Gmail Contacts in Bulk
|From the Gooru:
Editing your contacts one by one in the Gmail interface is slow and tedious. Often times the updates and changes you need to make to your contact list would be better done in bulk, from a spreadsheet.
You can export all of your contacts right from the contact viewer and make edits in a Google Sheet. Be careful when you import the edits back into your account, the formatting has to be correct and you need to remember to merge the inevitable duplicate contacts.
Read more and see a demo here.