Woocommerce customisation on staging site. Then transfer to live site

The current staging site was set up to update Woocommerce, Wordpress, and redesign the site theme via Beaver Builder. I need someone to perform some small code and css changes on the staging site prior to transferring to the live domain. The code/css changes are as follows: Product Page 1 - The existing product page doesn’t have the woocommerce product reviews on it. Add the woocommerce product reviews to the page. Placed at the bottom of the page. 2 - Style the 'add to cart' button, dropdown bag size, price, and quantity button to match the attached GIF. This should be placed in the position it is currently located on the product page. Cart page 1 - Style the subscription dropdown and change to resemble the attached example layout. Also add tooltip functionality to this section, so that a description to shoppers can be provided. 2 - Add Product Add On (Cart Upsells) functionality from existing site. This is fully working on the live site and needs copied across to the new theme template. See the attached example layout. The current theme was set up with Beaver Builder and experience with this would be beneficial. Any changes made to template files must be done according to the Woocommerce guidelines so they aren't lost when updating in the future. Then - Once the code and css changes are finished. I need someone to migrate the staging site across to the live domain. As the staging site went through design and database changes during the redesign, this will need to be taken in to consideration. I can set up a second staging site for the migration to be tested before it is transferred to the live domain. Requirements: - Zero downtime on the live site (or very very little downtime) - All orders on the live site/database are kept up to date, and not reverted back to when the staging site was created. No data loss!