You can export metafield sets in a couple really simple steps:
1) Navigate to the "Sets" section of our app's menu;
2) Select a resource type you'd like to have metafield sets exported for;
3) Click "Export" button.

Next, a modal window will show up where you can select metafield sets to be exported:
4) Select metafield sets to be exported. If you'd like to export all metafield sets, tick the "Select all" box;
5) Start the export.
Once your export is completed, you'll get a JSON file which you can use to import metafield sets to another Shopify store.