There are (at least) two ways to customise Knoppix and make it behave differently when it boots.
- Configuration - Easy, cheap and non-invasive. Make changes to local configuration in /etc and load on boot with myconfig= switch.
Many common customisations can be carried out without re-mastering. Consider using saveconfig to store local modifications before learning about re-mastering. See this page for more information: Configuration Howto
- Re-mastering - More complex and expensive. Change the contents of the distribution and burn a new CD.