2003 chevy silverado

a friend gave me a wrecked 2003 silverado and i want to know how to remove the engine and computer and trans so i can put it in my 64 chevy nova any help

Pretty simple. Disconnect the driveshaft and crossmember from the trans. Disconnect the motor mounts and the headers. Disconnect all the wiring and anything not directly connected to the motor. I would say take the wiring harness and see if you can reuse the harness. You may still need to buy an aftermarket harnness. Take the gas tank as well since that is where fuel pump is located on these motors. These motors will starve using an inline electric pump.IMHO I would say to get rid of that 4l60-E and use a 350 or 400 turbo trans.