Heater core replacement on olds cutlass ciera buick century chevrolet celebrity pontiac 6000 models. Thankfully replacing the heater core is fairly straightforward although it will take more than one hour to complete lift up your buicks hood and disconnect its battery with a socket wrench open the passenger side door and remove the four screws from the kick panel underneath the glove box. Source replace heater core on 2002 buick rendezvous hi there well the heater core is located under the dash on the passenger side usually cased in a plastic housingyou may have to remove the glove box in order to have access to. Step 15 once removed pull back gently on the plenum assembly while keeping an eye out for anything that was missed such as ductwork once its released remove it from the vehicle pay close attention while removing parts so they can be reinstalled correctly note there will be coolant leaking from the heater core use an old towel to help control spillage