How to edit a custom Source Name in Candidate Job Application

Summary:

Within a Candidate Job Application the system allows 'New Source' to be added under some of the extensible Source Mediums eg. Third Party.

Once a New Source is added, it becomes available in the drop-down Source list for future. Is it possible to EDIT these custom Source's once they have been created? If so, HOW?

Content (please ensure you mask any confidential information):

Recruiter manually creates a candidate, selecting a Source from the Candidate Dimensions Source Name list available. The Recruiter then manually Adds the candidate to a Job Requisition. The Candidate Source on the Job Application is showing as;