Must be all changeable as I stripped mine down to just the shaft when I cut mine (scary experience, measure 10 times and cut once).
In the end the whole fit was easy enough – I did find the steering rack a big learning experience though, figuring out what unscrewed from what, but most of that was due to the unit being caked in crud and grease so I could not figure out what was fixed to what.
It is another worthwhile modification though, after changing out the clutch to a diaphragm unit 🙂