Hi Terqel, unless you enjoy being a contortionist leave well alone. A new unit, with pretty well integrated circuitry to the rest of the system, will more than likely set you back at least a hundred if bought locally. Besides, a new one may not be significantly louder - if at all.
If you must feel the need to replace it, move the seat back as far as possible, and you will also need to remove the knee padding as well as the air distribution panel.
Then, carefully and gracefully slide your self under the steering wheel (head first, of course), place your back/backside close to the front edge of the seat, and wrap your legs firmly around the head rests, and ensure that the brake pedal is just, and constantly, touching the side of your face. This is one of those jobs that I describe gleefully if others are insistent on doing it. All in good humour, of course. Regards Styria