Q. How do you get rid of header images, e.g. that are collected in the “random” section of appearances?
A. If you have uploaded images and you wish to permanently remove them then:
STEP 1: Sign in to the dashboard for your site
STEP 2: click the Media button to open the Media Library
STEP 3: browse through the library to locate the image you wish to remove, mouse over it, and click ‘delete permanently’. Or, to remove several images at once, click the check box to the left of several images, then select ‘delete permanently’ from the Bulk Actions drop down, and click the Apply button.
This works for uploaded header images as well as for uploaded images used elsewhere.