WooGallery lets you add unlimited variation gallery images to your product variations. After adding them if you need to reorder or remove any images you can do it easily. Follow the instructions below: 

Reordering Variation Gallery Images: After adding the variation images if you need to reorder them you can do it simple by drag and drop in between the images and place them as you want. 

Removing Variation Gallery Images: After adding the variation images if you need to remove any of them you can do it simple by a click on the cross sign.