GE Addon Switch w/ Dimmer

You can determine which option you have by looking at box one of you switch. Notice option 9 has 3 white, 3 black, 1 red and grounds. Unless other system taps into it. Where option 3 has 2 white, 2 black,1 red and grounds.
With option 3. You can go to this post and see if it will help

For option 9 - connect all the white wires together at both box. And have a pigtail to your master switch. White is your neutral.
Red will be your traveler. Connect to traveler at both switches.
One black will be your line hot. One will be your load.
The last black from between the 2 boxes is now your spare. You can cap off both end.

Just a note. Before to do this. Be sure you have the correct wiring option as per the drawing or you could toast your switches.
Hope that will help