The most difficult part of the job is removing the plastic covers on the seat backs. Lift up and pop them out. Do not take a screwdriver around the outside or you will break the plastic clips. The panels are over $100 to replace if you break them.
Once the panels are off, it's in easy job. The headrests pop out when you insert an ice pick or paperclip into the release holes. Slide the new ones in...route the wiring down inside the seat frame (be careful the frames have sharp edges). There are holes in the bottom to bring the wire out under the seat. Route all wiring under the seat track and under the sides of the center console. Pop out the center cupholder tray and mount the brain under there and connect the wiring. Power harness runs from there to your fuse block. Negative goes to ground and "+" goes to a switched lead. If you have the GM factory kit there are instructions to top into the junction box located next to the brake pedal.
Total install shouldn't take more than a couple of hours, start to finish.