How do I Remove the Heater Core on a 97 Audi A4?

1. Park your Audi A4 on a level surface and open all four doors, then moving the front seats as far back as possible. You will also need to recline the seats as far back as possible.
2. Open your A4's hood and disconnect the positive and negative terminals of the battery. Locate the hoses that are next to the battery, which serve as the heater core hoses. Loosen the clamps on these hoses using your hands and slide the hoses off of the heater core lines.
3. Loosen the 8 mm bolt that secures the refrigerant lines underneath the heater core hoses, then remove the air filter that is located inside of the component that's revealed. If the air filter looks dirty, it may be an opportune time to replace it with a new one.
4. Remove all contents from your A4's center console armrest, the glove box, and back seat area.
5. Remove the plastic dash panel on the driver's side that is directly under the steering wheel. These are secured by three 8 mm bolts that sit at the left, center, and right hand sides of the dash panel.
6. Open your glove box and squeeze its sides inwards, which will loosen the glove box and drop it to the ground. Next, remove the four 8 mm bolts that are behind it. There are two bolts on the outside edge, while the third bolt rests on the driver's side corner of the glove box area. The fourth is located inside the glovebox cavity.
7. Remove the rear ashtray that is attached to the center console and designed for use by rear passengers. Remove the two 13 mm nuts that are revealed once the ashtray is removed.
8. Pop off the plastic dash paneling that surrounds the center console by using your flathead screwdriver, then remove the 8 mm bolts that are revealed (there is one on the driver's side and one on the passenger side).
9. Pry off the dash material which surrounds the shifter using your flathead screwdriver and set it aside.
10. Loosen and remove the two 8 mm bolts that secure the dashboard to the front of the car's interior. These bolts are located on the driver's side and passenger side of the car.
11. Remove the steering column on the driver's side by pulling it directly out, then loosening the screws that are revealed once the column as been extended.
12. Locate the bolt that is located behind the area where your A4's center three vents are placed. Loosen and remove this 8 mm bolt, then disconnect the wiring harness that is revealed.
13. Pull the dashboard cover forward towards the interior of the car and pull it up at the same time to remove the dashboard cover.
14. Reach into the center vent area of your car and locate the heating and ventilation box that is at the center of the car. This will be a metal piece with a box like structure and is secured to the car using a three-angle bracket and metal cross-bar. Remove the bracket by using your 8 mm socket wrench.
15. Pull the heating and ventilation box, which is constructed of black plastic and has a square shape, out of its place. Disconnect any wiring harnesses that are attached to it so that you can completely remove the heating and ventilation box.
16. Unscrew the heater core's securing bolt and drain any remaining coolant out of the heater core by pouring it on the ground.
17. Slide the old heater core out of its place and put the new one back in. Repeat these instructions in reverse to reassemble your car's interior, ensuring that you connect any wiring harnesses that you may have disconnected during the procedure.