Hello Camroon,
I did it just a few minutes ago.
Backup your entire galery directory before processing. In case of troubleshooting, it's allow you to install your oldest version.
After downloaded on your PC the imagevue_18.zip, unpack it and go to the upload folder. Upload all the folder (but not the "content" folder) on galery directory on the web.
Upload your old *.ini files you modify on your site (sitemenu.ini, config.ini,...) and passwords.php wich is in admin folder. This operation restore the params you modify in your old imagevue galery.
I hope it was clear for you because my english is not perfect as you can see
