Hi Kevin,
There is bunch more in your in your gridview file that’s going to need to be changed and I won’t be able to help you preserve your specific customizations. You have two options:
1. You can just rename this gridview file to gridview.phpOLD so the plugin does not use your customized copy and instead uses the core view file.
2. You can do the work to compare your gridview.php file with the core file in /wp-content/plugins/the-events-calendar/views/gridview.php and merge the new code with your older customized code.
I hope that helps but let me know if you need anything else.
– Jonah