This hides the text, but retains the code in case you ever want to erase the new code and show the header again. Click "Save" for WordPress.com or "Update File" for WordPress.org.

Scroll down to the "Header Image" area and then click "Upload." Select an image that you want to use for the header. Click "Open." The image is added as a top banner on your Tumblr blog.

A panel will appear on the right. For Image Search, enter what you are looking for in the search box. When the results pop up, select an image and click the Add button to add an image into the header.