Install Error: Destination Folder Already Exists

I am trying to install the WP SEO plugin by Yoast.

I had the plugin already installed and noticed there was a new update. I updated the plugin and was given an error message. The error also deleted this plugin from my plugin directory.

I tried re-installing the WP SEO plugin by Yoast and was given another error message saying the destination folder already exists. However I cannot find this in my plugin directory and do not know how to uninstall the file with out doing so via the directory.

What is the best way to fix this so I can activate the plugin again.

Thank you for your help