I have a virtual server with Linux CentOS 4 and I need to install PHP's mcrypt on it. Since it's a virtual server I didn't figure I'd need too much help so I didn't opt for the service plan that provides help. The support dept told me I could install mcrypt using YUM (YUM is already installed they said) and that I'd have to do it myself.

I do this from SSH command line?

Thanks for any advice.