Is there a way to change the url structure of a theme?

hi there, i have a site i'm working on called I am trying to change the url structure, but it looks like it's a part of the theme. Can you lead me in the right direction to possibly do this? I can give you the login info to see: This is what i'm trying to do. Change --> should become --> should become --> should become
The theme is called Caja by Luis Zuno