Hi folks. My ancient Blaupunkt cassette deck has died and I'd like to replace it. But first I need to get it out of the car. The deck is one of the post varieties where you remove the knobs, a couple of nuts, and the deck should push out the back of the opening. My questions are - Do I need to take off the HVAC unit below the deck first? And if so, how is that done? Is this a crazy project for a novice to undertake? thx!