A 12 ton press, or access to one.
After failing with two smaller presses I put my lower triple clamp and steering stem in the big girl and crushed the alloy "spacer"/support I'd made.
I then positioned it straight on the steel plates, applied pressure till I was a bit scared, hit it with the heat gun for a while and - success. It moved for the first time in 35 years (I assume).
Soon I'll have tapered bearings top and bottom
