How to install the Alternate Hreflang SEO tag extension through the Magento Marketplace
1. Log in to your Magento back-end Panel.
2. Go to System » Magento Connect » Magento Connect Manager.
3. Log in to the Magento Connect Manager using your admin Username and Password.
1. Purchase the extension through the Magento Marketplace.
2. Get the right extension Magento Connect Key from your account through https://marketplace.magento.com/customer/accessKeys/ under the "My Access Keys" tab.
3. Copy this key to your clipboard.
1. On the top of the Magento Connect Manager, click the Return to admin link.
2. The extension is all set and can be found in the back-end under the Magmodules tab.
1. Paste the obtained extension key in the open the text-field under the Install New Extensions tab.
2. The Extension dependencies appears: your package is in Ready to install status. Click to Proceed.
3. Wait till you get the successful installation notification.
4. Click Refresh to finish.