Like the others mentioned the only way to truly bi-amp is with an active crossover and separate amplifier channels for all the drivers. First you would need to bypass the internal crossover and program the active crossover using a loudspeaker management system. To do this you would need some knowledge into electrical theory, crossover and loudspeaker design. You would also need schematics and/or measuring equipment.
There are benefits to this but it is not a novice project and quite costly as well. I have seen this used in a commercial efforts that have been modded but mostly for DIY speakers built from the ground up for home use.
