Please overwrite your existing copy either using FTP or the WordPress Plugin uploader. The easiest way is via the WordPress plugin uploader. If you want to be on the safe side with protecting the code blocks work you have already done, then you may consider backing up your database OR at least take ‘copy and paste’ backups of your code blocks.
If you decide to use the WordPress plugin uploader, it is recommended to first click the gear cog icon called ‘General plugin settings’ and make sure that the ‘Wipe out data’ checkbox is NOT checked. By keeping this UNTICKED will retain all your code block information when you deactivate and delete the CJT Free plugin. This is more or less a precautionary measure, so if you do not have any code blocks or templates then this action is not required.
Once you have deactivated and deleted the CJT Free plugin, upload and activate the CJT Dev plugin that you purchased and downloaded. Go through any upgrade steps if required. You should now have the new CJT Dev plugin installed and all of your original code blocks intact.
Please use your license key so you will be alerted to updates from now on. Thanks for purchasing.