How To Bypass Stock Is300 Amp?

[iswhip300]

I bought a new headunit for my 2001 lexus is300. i pulled out all the trim, had the new headunit in place(pioneer PH-400DVD) all the wires hooked up correctly, but my headunit didnt have a slot for the amp connector. The headunit turns on and everything, but i know the amp controls the sound....

so what im asking is how can I bypass the amp straight to the headunit/

i know i can run separate wire from each speaker to the headunit

anybody else have any ideas?

thanks