a)How to hide the Blogger Navbar
1) Login to your blogger dashboard.
2) Click Dashboard ->> "Design"
3) Click "Edit HTML"
4) Search for <b:skin> as you see in the image to your below. The code will be quite near the top of your HTML section, you shouldn't have to scroll very far at all. The blue code should definitely be there, but the data box you see may not be, depending on where your template came from.
5) ADD the Blue code as below on the place you see on the image below.: