Updates for Restrict Content Pro will normally appear in your WordPress dashboard, provided the plugin is licensed in Settings > iThemes Licensing. If you need to upgrade the plugin manually, you can do so following these steps:
Install and activate the plugin Easy Theme and Plugin Upgrades. This can be installed through WordPress Dashboard > Plugins > Add New.
Next, log in to your iThemes Members Panel and select Downloads. Then find your Restict Content Pro Subscription to download the latest version. For more assistance, please go to Download Restrict Content Pro from the Members Panel.
Back in WordPress, go to WordPress Dashboard > Plugins > Add New > Upload Plugin, and select the .zip file you just downloaded. Click "Install Now" to upload the plugin.
Once the new version is installed, you may deactivate and delete the Easy Theme and Plugin Upgrades plugin if desired. This plugin automatically handles the process of replacing the old version with the new one when you upload the .zip file. It's no longer needed after the new .zip file has been uploaded.