When I download the zip, some say simply to replace the file others say replace after customizing.
Looking at advforecast2.php - it says to just replace the file. However in the file it looks like there are customizations. So do I need to change anything?
If you’re using the Saratoga templates, then the needed customizations are all in Settings.php for scripts that say ‘just replace the file’. The settings in those scripts are for non-Saratoga/standalone use and those internal settings are overridden by $SITE entries in Settings.php.
For the ‘replace after customizing’ scripts, just copy the corresponding settings from your old script to replace those in the new script and upload the updated script.