Bose Radio Removal Question?

Hello all First off I would like to say Hi and I am new to the site so hope you can help me out here.

I just purchased a 2005 EXT Trailblazer with a Bose radio System in it. I am looking to remove that and try and use the existing speaker wire to the tweakers and the door speakers and add Kicker Speakers. I will be adding a new Kenwood head unit as well. I hooked it all up and found out that the speakers will not work but my subs do. After more reading I found out that the Radio actually does alot of memory stuff with the truck. I guess what I need to know is how do I get my new radio to work with those speakers on the door and tweeters. Is there a special Harness I need to buy or if you know anything please let me know.

Thanks
Josh