Stock amp and new head unit

This has prolly been ask a million times i havent had much time to search but i need help! i bout a new head unit and got the wiring harness. But do i just plug the new wiring harness into the old one or do i have to unplug the stock amp????

basically you going to need some way to connect the wiring harness for the vehicle to the wiring harness for the new headunit by either crimp connects or soldering.(pretty easy) once the harnesses are connected together you will be able to plug it in to the OEM harness on the truck. btw your going to need a antenna adapter and a dash kit also.

I understand that i have the wireing harness atenna adapter and dash kit i just want to know if i need to unplug the stock amp.

nopee. but you will need to hookup the illumination(never thought it worked is why i say it) and the amp turn on lead. that stock amp still needs that wire. i spent a whole day trying to figure that one out haha.

Thanks Man