In this tutorial you’ll learn how to upload a custom header image to your blogger blog.
1). In your dashboard, go to Layout.
2). In the Header section, select Add a Gadget, and then select the Page Header gadget.
3). Select From your computer, then select Choose File and upload your header image.
Underneath Placement, be sure to select Instead of title and description.
Also, make sure Shrink to fit is UNCHECKED.
4). Save your changes.
Your header image has now been uploaded.