How do you add the CSS, JavaScript, and HTML for the Course Description Customizations?

I am looking to implement the GitHub code for the Course Description Customization (found here https://github.com/unsupported/catalog/tree/master/branding/course_description).  I've added t...

"Sorry! The enrollment period is currently closed. Please check back soon."

Has anyone had any success removing this message from the Catalog course listing?  I've been told it's possible with CSS, but I don't see how.   Any help is greatly appreciated! ...

Changing the color of the catalog footer links

Hello, Has anyone had success with changing the color of the first line of links in the footer of the catalog?  I just want the two lines to match and be visible.  I've changed the color...

How do I add a background image to the Home Page feature area?

How do I add a background image to the Home Page feature area (the area below the header and above the search bar)?  I've called to it in the CSS code, but how do I upload it to the Canvas serve...