How to Uninstall Asterisk?

Hi
I want to uninstall asterisk server. i think i have messed up with some of the settings and files. Asterisk does not start now. So i want to uninstall and then start the installation process all over again.

Well actually it was working fine when i only installed

asterisk
libpri
zaptel

it used to start fine. We used land calls and use dialplan configuration and etc…those were good days.

then i tried to install h323 support for asterisk i used the following link to do that:
astrecipes.net/?q=astrecipes/com … with+oh323

it wasnt installed and threw errors of some kind. During the h323 installation, the installer itself has made some changes with configuration and now it does not start.

i have to uninstal everything and then start the process again.
i need help for uninstalling the asterisk and all related packages…
plz help