Have you got the centre section piece too? Or is it a back box and under axle pipe? If it's a used system make sure you get yourself some decent new clamps for it too! Or you will be jacking it back up and replacing them also!
The system is in two pieces, precat, cat and two silencers on the first and silencer and back box on the back end, I guessing yours is the full back end which should be a real easy job! Lots of WD for the exhaust bracket rubbers!