Modules are very easy to upgrade but we encourage you to read this article carefully. First we want to focus on don'ts since from time to time we see customers breaking their installations of WHMCS or losing data just because they upgrade in inexplicable ways.
Do not deactivate the module. Module's deactivation has nothing to do with upgrade but rather permanently removes data from. To undo this operation you'll need to restore from backup.
Do not upload new files in fancy ways. We've seen customers uploading files one by one in wrong directories and clicking "No" when FileZilla asks them to overwrite files. If you don't overwrite files you're keeping old files meaning that the upgrade won't occur.
Begin by downloading the latest version from our website. Click here, select your module and click Manage button (requires login). You can see an example in the screenshot below.
Next page lets you download the latest version of the module giving you multiple download options depending on your PHP version. If you need help choosing the right package, click here or Help me choosing visible from the screenshot below.
All downloads are safe. Files are verified multiple times per day automatically. For security reasons we won't share details.
Extract the Zip you have just downloaded and open the extracted folder that has the same name. You should find a directory named modules. This is the folder that needs to be uploaded on your server.
Use an FTP Client like FileZilla to upload modules folder to the root directory of your WHMCS. The root directory is the one with configuration.php file. When the overwrite confirmation prompt is shown, confirm you want to overwrite all files.
That's it. You have successfully updated your module to latest version. Changes to database are automatically applied by the intergrated Auto-Updater when necessary.