Hi Bondy, As I mentioned in a previous post/topic I fitted Pyramid taper roler brgs as well when Inmotion didn't have std ball & race in stock. Anyway has been said it was very difficult to get the old bottom cone/race off my M92, I used heat from a stripper gun plus brute force with hide hammer hitting the top of the steering head, not very clever and it could've ended badly! It did come off though. Don't recommend that really - Would do it again differently ......also I'd use std. ball & race type not taper brgs.
As an aside, I strated to do the same thing for my vintage Yamaha and when trying to lever the race off the bottom yoke the race just broke in half ! So, it's possible you could just strike the race with a hammer and punch and the hardening+ material may make it quite brittle (but hard)? Might be worth a try? As long as you dont get carried away and at your own risk!