Question about Active Bi-amping

Curious about Active Bi-Amping.

My understanding is that to setup an actual active Bi-Amp (with compatible speakers), you would need either 2 mono block amps per speaker or 2 stereo amps and a External Crossover?

Would the Crossover in the Speaker need to be bypassed or removed?

OR

If you were to do Passive Bi-Amping, you would connect each amp directly to the speaker terminals but how would you connect the Amp Signal connections back to a pre-amp or Integrated since most are only have a a simple left and right output?

Thanks