How do I change my Tezos to BTC?

Could you please explain to me how I can convert my Tezos into Bitcoin? I'm a bit unfamiliar with the process and I'd like to understand the steps involved. Do I need to use a specific exchange platform? Are there any fees associated with the conversion? Also, how long does the process usually take? It would be helpful if you could provide a step-by-step guide on how to go about it. Thank you for your assistance.