You can edit your candidate profile even after they have been added to Recruiterflow.
Just open the candidate profile and click on the 'pencil icon' next to the candidates' name.
Details like Candidate name, current company, source, social profile, expected compensation (visible to only admins, recruiters and hiring managers) etc. can be edited from here.
Just hit save when you are done.
All changes to the candidate profile are logged automatically into the acitivity log.