A. Use the command Hotfix /remove to remove a hotfix. Before you can do this you will need to expand the original hotfix file using the <hotfix> /x command.
To force the remove using the registry editor (regedt32) HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\HOTFIX and delete the entry for the HOTFIX. Then use explorer to goto %SystemRoot%\HOTFIX\HF00?? and copy the backed up files back to their original location.