There is currently no function available to edit or delete your comments once posted. The only exception to this is for the mandatory comments that you post when you place an offer on a task.
When you withdraw your offer, the comment attached to the offer will also be removed. You then have the option to make a new offer with a new comment.
If you wish to have your comment removed, whether because it is no longer relevant or because you’ve realised it does not comply with our Community Guidelines, whatever the reason, please contact us for assistance.