In order to run this update, we first need to create a query that finds the specific contacts you would like to update. One common example of this query is all contact entries that have a specific contact subject text; the steps to create that query are available at How do I query on journal contacts with a specific subject?

Once you have your query that finds the contact entries, we can run the mass update to change the Contact Method:
  1. Click Management
  2. Click Mass Update
  3. Click Update Existing Contacts
  4. Select the query that you created from the Category and Query drop down menus
  5. Below the Update Type heading, select Assign
  6. Below the Contact Values heading, select the Contact Method that you would like to assign to all of the Contact entries (do not fill in values for any other fields unless you would also like to update those fields)
  7. Click Next
  8. Preview the list of entries that will be updated
  9. Click Next to run the update