1 - Open SQL Management studio
2 - Find your portalFX database
3 - Make a backup of the database
4 - Right-click on the portalFX database and choose New Query
5 - Paste the following code in the query window
WHERE (PermissionKey LIKE 'CanSetAlertPreferences')
6 - Click execute
7 - Now all users will not be able to change their alert settings.