You can find the fitting instructions here....
apexi-usa.com/product-support-2/
I have fitted an SAFC to our 2 but not the SAFC 2, cant see there being much difference. I had to extend the wires from the unit to reach into the boot and connected the wires at the ecu. All the wires you need are there and you have a bit of room to work as well. I ran the extension wire along with the loom that passes from the cabin behind the passenger seat to the engine bay, below the fuse box and into the boot to the ecu.