How to remove a theme from github pages

I accidentally chose the Cayman theme for my github page at https://benmuiruri.github.io/Wangari-Maathai-Tribute/

I would like to disable the theme and use my own custom layout. 

How do I go about disabling a theme / removing a theme and using my layout? 

This is essentially a duplicate of a previous topic. That topic will show you how to remove the theme. Once that’s done, you can follow the instructions in the Pages help documents on how to customize your Pages site’s layout.

I hope that helps!