From my understanding spirits can be bound to bodies like the Shedim and Zombies and stuff. Is there a ritual or method to remove spirits from their bodies? So you could unbind someones spirit, bind it to another corpse for a duration, install cyberware on the original body, and then rebind the spirit to the original body, thus retaining your magical ability despite cyberware? ...Am I crazy?

You're crazy. If someone goes astral and then you install cyberware, they'll still lose the essence (and thus magic). The only question is whether this happens immediately or after the mage returns to their body.

~J