Unfortunately, the MPLAB SIM User Guide is outdated, circa 2003.
Many of the features shown throughout the guide are now incorporated into the "Stimulus Workbook."
Debugger->Stimulus->New Workbook
Once the workbook dialog box opens, view the various tabs, Asynch, Pin/Register Actions, Advanced Pin/Register Actions, etc.
The Asynch and Pin/Register Actions has replaced the dialog box shown in your photo.
For more up to date information concerning MPLAB SIM, Help->Topics...->Debuggers:MPLAB SIM hit OK
There you will find the method to toggle pin levels using the current version of MPLAB SIM.
BigDog