4 days with no answer...disappointing, but not surprising.
I'm assuming you've already found this by now, but just in case someone is searching the forum in the future...
1. Click "Components", then click "K2" to open the K2 dashboard.
2. Click the "Users" tab at the top of the K2 dashboard, then click the name of the user you would like to edit.
3. Change the information, description and photo for the account.
4. Scroll to the top of the screen and click "Save"