How would I go about removing cpanel from a CentOS 3.1 machine so I can later install Plesk 7? The company I have the server with wants to cahrge $75 for an OS-Reload so I'm looking to remove it manually.

There is no data on the machine so that's not a concern. :)

Save yourself a headache and cough up the $75.

Cpanel modifies and add quite a lot of files. There's no real easy way to uninstall it. It affects the Apache setup, the email MTA especially, and more. You are likely to face issues later on. Get a reload is probably a better way to go.

Agreed, any major control panel is not meant to be removed. The idea of the control panel is that it integrates with everything, unfortunatly it is so integrated removing it is nearly impossible.