Follow these instructions to install Justuno manually on Magento:
Follow this video or the steps below:
If you are using Magento 2 please use this article
1. Login to your magentocommerce account
2. Login to your magento admin panel..
3. Login to Magento Connect from magento admin panel with your admin credentials..
4. Now for your Magento Commerce account, click on Install Now button, agree to agreement and copy the Extension Key
5. Paste the copied key to the field given to paste the key to install under "Install New Extensions" section
6. Click on Install.. It will show summary of extension..
7. Then click on Proceed to Install
8. As you see the message "Cache cleaned successfully".. this means you have successfully installed the extension..
9. Once installed, please logout of admin panel and login again..
10. Navigate to Configurations.. you will find a new tab for Justuno Settings
11. Enter your credentials to login and save the config..
12. And it is done!