Its on the top of the engine at the right front... coils and ignition module are together. Follow the plug wires, away from the spark plugs, where they will connect into the coil pack. The ignition module is sandwiched under the coil pack. To remove either... remove the three nuts under the ignition module and the six torx screws on top of the coil pack.... voila.
After market new modules (10/2010) cost $98-134 at Carquest Auto Parts.
OEM Delco module cost New from B&B Auto parts $ 360