Of the EPS units, I've seen the link on the MICU somehow. Well they're accessible via the the HDS anyway, I'm imagine it's just a BCAN bus thingy rather than any direct control. However, the EPS is also speed sensitive, so the the EPS module must have some sort of speed input to control the amount of power to push to the rack.
Apart from the mechanical fixings (i.e. remove old rack and new tie rods, and new aux belt, add power, etc). You'll need to see how to configure speed into the EPS.