Hello,
Yes, you can change the PHP version using WHM "Apache Update" or using command "/scripts/easyapache" from the shell. You can select the PHP 4.4.6 or PHP 5.1.6 or PHP 5.2.0 which are stable versions of the PHP.
If you are having any problem while updating PHP, just send a mail to <a href="http://www.eukhost.com/vps-...a>@eukhost.com; we will be there to help you.