XDJ/ Traktor/ DJM Setup

Hi, I would appreciate some help setting up 2 XDJ 1000 MK2's and a DJM 750 mk2 mixer with Traktor.

I have each XDJ connected to line 2 and 3 of the mixer with RCA cables.

I have connected my laptop via USB. How do I get the both XDJ's to work with Traktor and the mixer? 

cheers