Unfortunately GM did not provide any provision for removing stuck Cd's from these units. 99% of the time, it ends up being necessary to remove the CD player and send it to an authorized repair shop and have them disassemble it to remove the CD. If you decide you want to go that way and need help removing the unit, drop me a note and I will send you instructions. I will need to know if it is a unit that is built into the radio or if it is a remote mounted CD player. Below are a couple of methods that some other people seem to have had some luck with. I don't endorse them, but they may be worth a try. Up to you. Remember also, if the truck is under warranty and the fault is in the player, that GM will take care of it, if the fault is in the CD, you will pay the bill. Thanks
Find a Popsicle stick or something thin but rigid and tear off a few inches of Scotch Tape from that roll you keep in your junk drawer (next to all those ruined CDs you intend to make Christmas ornaments out of some day). Put the tape on the top of the stuck CD using the thin stick to help attach the tape firmly to the disk. The idea is to lift the CD enough to enable the player to eject it.
Try using some tweezers, needle nose pliers or hemostats (every tool kit needs a hemostat or two!) to pull the CD out while pressing the eject button with power going to the player (theory being that the disc is so slick the player can't eject it without help). Some people report success just by pulling the disc out with the tweezers without power to the player and without pressing the eject button.