yes it isnt great....
Windows:
you could uninstall if you insert the DP media but this is time consuming. Windows programs "change" wont work if you have the patch installed. There is a way to run a remove_patch.bat which is in utilns dir. Run it "remove_patch.bat b908" but even doing that you still need to uninstall component then reinstall the 908 patch too....
best bet is to remove then fresh install of agents from the cell manager omniback share...
Linux:
rpm -qa | grep OB2 will show filesets installed. Run a rpm -e <fileset> for what component you want removed. ie "rpm -e OB2-OR8-A.09.00-1" then run an omnicc -update_host <client> from the cell manager
HPUX:
again same as above but use swremove to remove filesets not needed
HOPE all this helps....if so, please click KUDOS! thanks and Merry Christmas!