How to select all instances of a variable and edit variable name in Sublime

Question

If I select a variable (not just any string) in my code, all other instances of that variable get a stroke (white outline) around them:

Answer 1

It's mentioned by @watsonic that in Sublime Text 3 on Mac OS, starting with an empty selection, simply ⌃⌘G (AltF3 on Windows) does the trick, instead of ⌘D + ⌃⌘G in Sublime Text 2.