Here are the steps that you need to take:

1. Make sure that you have installed the WooCommerce Subscriptions plugin.
2. Purchase the WooCommerce Payment Plans plugin.
3. Download and install the plugin.
4. Select an existing product that you’d like to make available on a payment plan.
5. Edit the product and go to the Product Data > Payment Plans page.
6. Add a payment plan to your product.
7. Watch your conversions magically increase, along with average order value (AOV) and customer satisfaction.

Learn more about how to set it up by viewing the documentation.