well from my understanding all the speaker wires from the Rockford HU run to the factory 300 watt (2ohm) amp via harness and output via harness as well

i want to overide the factory inputs for factory amp for the Front speakers and them run thru another amp i will install my self for the front speakers and then re wire the the rear speaker inputs from the HU into the amp then rewire the outputs to work in 2 channels instead of the factory 4 ... and buy dropping to 4ohms i figure the ampage be about 150-200 watts instead of the 300 watt 2ohms ... thus giving me 75-100 watts for rear speakers output and about 50 watts from the 2channel 100 watt lil amp i will install in the under the passenger front set

IS it possible to make this work?