Hi,
It's not PEAR SOAP that you want. It's the standard SOAP extension for PHP.
A lot of hosting companies already have it installed on their servers. If that's not the case, the simplest is to ask your hosting company if they can add it to your hosting.
Sometimes, you might have to install it yourself. Based on the server you're using the setup will be different.
For example, on a wamp server, you just have to activate it in the list of the PHP modules included with wamp.
Otherwise, on a lamp server, it will vary based on the distro you're using.
For example:
stackoverflow.com/questions/11014431/enable-soap-on-php
kb.mediatemple.net/questions/1947/Config...with+SOAP#dv_managed
But you'll find many more explanations online based on which distro you're using and they will be more accurate.