Product return for exchange

Hello WooCommerce gurus!

I have a problem, and im surprised of the lack of the information about this….

I costumer buy shoes. Order completed. Product sent.

Costumer returns the goods, and ask for other shoe number.

How do i processe the exchange for the product?

Exp. a 43 its returned (back to stock), i send a 44 (reduced from stock). Need a package slip (already have the plugin) for the shipping.

https://www.ads-software.com/plugins/woocommerce/