Shopify Birthday Suit is an exceedingly bare bones Shopify theme intended for use by theme developers as a basis for their own theme development. It is not intended to be used "as is", rather as a building block. Feel free to modify and use for your own means.
The theme references a shop.js and style.css file but these are empty, consequently the theme is rendered with default browser styling. This is intentional.
To install the theme download the ZIP file and upload the same ZIP file to your Shopify store. Full details on uploading a theme can be found in the official Shopify docs: http://docs.shopify.com/themes/the-basics/build-your-theme/upload-theme.
Shopify Birthday Suit was created by Keir Whitaker