Step 1: Login to the WordPress admin dashboard
Step 2: Click on WooCommerce (or over the menu item)
Step 3: Click on Orders
Step 4: At this point, you will see a list of orders (if you have any). Under the column labeled Order, click on the order that you wish to edit. This will bring you to the details for that order.
Step 5: After you have completed making your changes, click on update in the top right corner of the Order details page