If you just integrated your store but haven't made any changes to the products you added, you can simply uninstall the app, set your currency on Shopify and re-install the app to have it convert the price of all your products. Please do not do this if you have made extensive customizations to the products in your store already. 

If you've made extensive changes to your store but would still like to convert your currency, contact us at support@modalyst.co and we will make the change for you without overwriting any of the changes you made to your products in-store.