Awesome screenshot edits :3! and daww love the cute hyena family pic heheh.
If you want to change Carly to Rusty you have to press where it says "profile" at the top left of your profile. From there click where it says "account related settings" and then you'll see an option "Username: Name This is the displayed name that people will see" in the white space just type in Rusty and then scroll to the bottom of the page and click "change profile"
Hope the helps. (btw sorry couldn't mail you since I'm on mobile screen is tiny Dx)