PHP 4.3.9 to 4.4.7 or greater

[sypder]

I am running Plesk 8.0.1 on RHEL4, and need to upgrade from PHP 4.3.9 to 4.4.7 or greater. This is on a production server, so I need to ensure the upgrade is flawless, I do not have at the moment a test server to practice this on. What are the steps to perform this upgrade, can it be done from within Plesk?

Thanks.