Go to your member area on yithemes.com.
Go to "Licenses & Downloads" and click on the "Download plugin" button next to the plugin you want to download.Note: if you're using Safari on Mac and you don't get a .zip package, but you just see a folder in your Downloads, it's because the package if automatically unzipped. You can either create a .zip package of that folder or change your browser settings.
Go to Safari Preferences > General.
Scroll down to the bottom and uncheck the Open safe files after downloading box.
Now, you can download the plugin once again and you will be able to get a .zip file to upload into your WordPress dashboard > Plugins page.