To change the order of the products in your video you first need to add your products. Once all of your products have been added a carousel of your selected products will show underneath your video.
Here you can click/touch, and drag product boxes to rearrange the order in which they will appear in the store section, in your video.
TIP: make sure the order of your product seen in the in-video store matches the order the products are physically shown in the video.