Cleaning up old versions

Hi

I have been asked to clean up a network.  In the past AV has been manully installed on all PC's.  There are no removal passwords.  But versions are a mix of some 11 and  mostly older V12.  There is no central managment. 

We want to script the removal of all the current AV's (all devices are domain memebers).  We have a new managment console setup.  Once we have removed all old versins we will push out the new.

We have looked at cleanwipe, but it can not run silenetly.  

Is there some way to script uninstalling of the client?