resetSim isn't a button, rather a command. In your game, press Shift-Ctrl-C (or Shift-Ctrl-Windows button-C if on Windows 7 or 8 ) and a command line will appear at the top of the screen. Type in resetSim, then a space, then whatever your sim's full name is.
For example: resetSim Christopher Steel
Press enter, and that sim will reset back home. This also helps if the sim becomes stuck in any way.