download the file .tar.gz from NewRelic site
you must download the osx version before installing the NewRelic
unzip the files then get into the directory using terminal
run this command:
$sudo NR_INSTALL_PHPLIST=’/Applications/XAMPP/xamppfiles/bin’ ./newrelic-install install
when the installer asking to install Daemon, choose ‘y’ (yes) .. wait until the installation complete. In this process the script will modify your php.ini automatically by inserting new module so our php application will sending data to NewRelic server.
The last step is stop the XAMPP apache dan start it again. Your NewRelic will be ready to use.
To make sure the new module is running, try to phpinfo() then look for NewRelic extension