How to redeem stETH to ETH?

Could you please explain the process of redeeming stETH back to ETH? I've heard about staking Ether to earn staking rewards in the form of stETH, but I'm not quite sure how to reverse this process if I want to convert my stETH back to ETH. Is there a specific platform or exchange where I can do this? Are there any fees or waiting times involved? Could you provide a step-by-step guide on how to go about it? I'm a bit new to this crypto staking and redemption process, so a detailed explanation would be highly appreciated. Thank you in advance for your help!