Ewwo...

I have a problem with getting IMP (Internet Messaging Program) running on my server.
I want to install this program for my e-mail service. So I went to the official website [http://www.horde.org] to find all the stuff I need.
Once everything downloaded and uploaded to my server I found out that PHP 4.2.1 has missing modules from PEAR, so I have to install them manually, or Horde will not work, and as long as Horde doesn't work IMP of-course neither. And there you got my problem. I can't figure out how to install those manually on my server..
So..is there any nice guy out here who thinks to know how to do it? Please contact me ASAP..Really need help.

Thanks in advance.