Updating your VPS isn't hard. You just have to ensure that you know what you are doing before you start making changes to your VPS, as you don't know how it will affect your site / VPS.

To update your VPS, please do the following (we presume that you are already logged into SSH):

# yum update

The above command will search and tell you what packages are outdated, once that's done, you will need to hit "y" to confirm that you to have them installed.