there ins no need to remove the door panel unless you are mounting the tweeters in the door along with the crossover. you can catch the factory wires going to the doors in each kickpanel and clip them there. one side then goes to the speakers, the other is the input to the crossover from the amp. use the side that goes to the speakers to go to the woofer in the door from your new crossover and just drop some speaker wire down from each side for the tweeters. done. the wires in the connector in the keckpanels will be the same color as the wires at each door speaker.