UPDATE: 09 March 2017
Just a simple code snippet for anyone that has installed the Yoast plugins only to find themselves getting annoyed at the nag screens to register the plugin.
First you will need to unzip the plugin.
Next you will need to locate the licence manager file:
at around line 305 you should see code that looks like this:
You need to change it to this:
Save the file, rezip the plugin and upload it onto your website or SFTP transfer the amended file onto your server.
You just need to remember that whenever you update the plugin this code will be overwritten so it’s something you’ll need to come back to again in the future.