League of Legends (LoL) Question: How can I change the skin displayed behind the table of contents?

If you use the default chapter creator in mobafire You sortof have to use the default contents page for that champion. But if for whatever reason you dislike that background or whatever, it's entirely possible to create your own custom table of contents.

Here's a brief guide if you wanna do that: http://www.mobafire.com/league-of-legends/forum/build-and-guide-discussion/10-second-guide-to-making-a-custom-table-of-contents-21830

Unlike the art displayed behind the cheatsheet, the skin behind the table of contents cannot be changed by users (sorry). Feel free to look into Thatdudeinthecotton's suggestion if you are not a fan of it.