Hi John,
Honestly replacing these bearings is rather over rated.
A good solvent clean out and forcing a small amount of grease in to it will have it go for another 20 years. This bearing only has load applied when the clutch is engaged and that time is generally minimal and as such wear and tare is also minimal.
A freshen up is all I've ever found that they require............unless they've suffered major water exposure.
Spending ridiculous amounts of cash on these machines is what this cottage industry is relying on.
Cheers,
BB.