To answer your question.......you replace the cable that will include the lower part of the rack. No need to remove the steering wheel. There are four bolts down below that can be removed and the rack will fall out the bottom. Then a mount in the rear and the rudder connection. There will be a bunch of zip ties holding the cable in place. Routing is important as is replacing the zip ties. Do not force it back through either. I would recommend a Morse cable over the Teleflex. Remove the old cable then measure it and get a new one. Better quality, and less likely to break. I always recommend adding in a zerk fitting so it can be easily greased at every service so the cable will never need replacement again. I found this item although I am not sure if it will work.
Zerk fitting The cable without the rack looks like this
Morse cable The cable with the rack will look something like this without the steering hub etc. shown in the photo
Morse cable and rack