To sell a put option, you need to follow these steps:

1. Choose a stock: First, you need to choose a stock that you want to trade in. It is recommended to choose a stock that you are familiar with and have researched about.

2. Choose an expiration date: You also need to choose an expiration date for the option. This is the date when the option contract expires.

3. Choose a strike price: You need to choose a strike price for the option. This is the price at which the option can be exercised.

4. Sell the put option: Once you have chosen the stock, expiration date, and strike price, you can sell the put option. You can do this by contacting your broker or through an online trading platform.

5. Collect premium: When you sell a put option, you receive a premium from the buyer. This premium is the price that the buyer pays for the right to sell the stock at the strike price.

6. Monitor the option: After selling the put option, you need to monitor it until the expiration date. If the stock price falls below the strike price, the buyer may exercise the option, and you may be obligated to buy the stock at the strike price. If the stock price remains above the strike price, the option will expire worthless, and you will keep the premium.