If you purchased the theme directly from the Shopify Theme Store, your theme will be automatically installed when you log into your Shopify admin.
Upload Pacific theme from files
If you purchased your theme directly from pixelunion.net, you'll receive your theme as a ZIP file named something like
pacific.v0.0.0.zip. Download this zip file, but don't unzip it. Instead, go to your Shopify admin dashboard, then Online Store > Themes. Select Upload theme to locate and upload your theme file from your device.
Your new theme will show up below your current theme as a Draft. At this point, it is installed, but not published.
To get started with configuring settings, adding content, and customizing the theme features, take a look at the next article on using the Theme editor.