Install new engine, how to disconnect old engine from tapered shaft.

I would contact the manufacturer. No way I'd attempt something like this without a service manual.

I have a Generac 10000 XL Generator with a 19 HP Briggs Straton Engine model 350445 and the engine needs to be replaced. I read about it being connected to a tapered shaft through the Generator. My question how do you disconnect the shaft from the Generator?

Is it less expensive to replace the motor than buy a new generator? If the motor
Has already failed what does the rest look like? This sounds like restoring an old car... if this is a hobby then good luck to you.