As far as I know - it is not possible. Once on the blockchain it is on there for good. It would however, be nice if we could edit our Steem blogs that are more than a week old since, if you are new, you are still learning the ropes and probably done a lot of mistakes. If you are a perfectionist like me, you want to go back and perfect the posts or improve on them. So instead of laughing at you, I ask those who see this post to please let us all know how, if possible, we can fix old posts - update them etc. I would be interested. I also thought it would be nice to delete and redo stuff. While we are at it, it would be nice if we could still earn on our blogs after the initial week. SteemIt - could you help us please?