You can edit the title, description privacy settings (changing to Public, Unlisted, Private etc.). You can also edit the video itself (trim the start and ends, for example).
- Log in to YouTube
- Click on the Trust logo in the top-right and select 'Creator Studio'
- Click 'Video Manager' on the left menu
- Find the video you'd like to edit, click 'Edit'
- Here you can change the Title, Description, or change the Privacy option
- If you want to 'Trim' the video (shorten start/end), then navigate to 'Enhancements' and use the Trim option
- Once you're happy with the edits, click 'Save' to apply the changes