I finally figured out how to change my picture with the new dashboard! XD
1. Go to your Dashboard.
2. Next to the word “Dashboard” is your blog name, click on it.
3. It will direct you to a different view. Under the “open your blog” tab, there is the “Customize appearance”. And under that “Customize appearance”, you will see the “Settings” tab. Click on it.
4. The portrait changer should be on there, first thing. Then just click browse, take the picture you want, then upload it.
Hope this helps! :3