WARNING: This page is about a different car, the 2006 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Block Heater Components
Courtesy of DAIMLERCHRYSLER CORP.
1 - BLOCK HEATER
Raise vehicle.
Remove power cord from block heater.
Remove bolt on block heater. Remove heater assembly.