If you are looking to update your theme, you can follow our guide on the steps in order to do so by clicking this link.
The latest version of the theme is always available as a free download for the store for which it was bought. Changing the theme version used in your store will involve some work on your part. You’ll need to re-apply your theme settings (homepage sections, typography, colours, etc) and any custom code or apps.
The Shopify platform does not provide a way to copy these settings automatically. The latest version will appear as an unpublished theme meaning you can work on it for as long as you need to without interruption to your live storefront.