Hooking up Stock amp for tweeters

Anyone ever done this? i've heard of people doing it, its fora  95-99 mitsubishi eclipse, the stock head unit runs a small amp under the passengers seat for the tweeters in the dash, just wondering how i can hook these up with my aftermarket headunit?

Ok Thats A Bad Idea Sometimes You Need TO Check How MAny Whats Your Stock Amp Puts Out Then You Can Decide Whether You Should Or Shouldnt, Because The Stock Amp Usualy Puts Out More then Stock Stereo So If You Put Too Much To Them Boom Boom Bye Bye Tweeters It Usually Doesnt Happen But Its Good To Know But If Youre Gonna DO It Anyway Just Run The Wire To One Of  The Speakers And Thats It, Its Rather Simple.They Can Hear His But Feel Yours Vermont Audio