Question About Speakers And Amp

if u wanna hook up your front and rear speakers to an amp right. do u disconnect the wires coming from the head unit to the door speakers and just hook up the speakers to the amp?


i just put two speakers in the front, removed the door panels to get to them. did the head unit myself
and put in a 2 channel amp for a 12'' subwoofer.
i ran the amp wires by the door sills of course. but i did not replace the stock wires that go to the speakers. if i wanted to would i just cut it as close to the head unit plug as possible? and run the new one? thanks