If you represent the profile as an owner, staff person, or board member, scroll to the bottom of the profile and click on the "Request management of this profile" link.
If you had a profile that you managed in MatchBook.org or CultureCount, the user account you used to update those profiles is already in CreativeGround. Just go to the log in page and reset your password if it's your first time logging in.
If you do not represent the profile but want to provide an update, scroll to the bottom of the profile and click on the "Submit a suggestion for this profile" link.
See here for detailed instructions: Updating or Creating a Profile