I have to replace the switch in my 03 silverado and i cant figure out completly how to remove the old one and put the new one in? I know there is a alan head screw on the switch but idk if you take it out or what? And when you change it do you have to get new keys ?

 

Ignition switch is what you replacing, not the ignition switch harness right? If it the harness you don't have to replace the key, if its the key tumbler you may have to switch keys. I changed the harness from my 97 Tahoe, the hard part was Allen screw tapered bolt that requires a special socket. suxs, but it was a breeze after that. Good luck.