Here's a brief how-to guide to deinstall QTSS on the OS X platform.

1. Back up config files sitting at /Library/QuickTimeStreaming/Config/ as needed. Also, the qtaccess privileges file present in the Movies directory.
2. Delete the configuration receipt at /Library/Receipts/DarwinStreamingServer.pkg
3. Remove the server and the webmin perl script:
/usr/sbin/QuickTimeStreamingServer
/usr/sbin/streamingadminserver.pl
4. For completeness, also the Playlist Broadcaster & friends,
/usr/bin/PlaylistBroadcaster
/usr/bin/MP3Broadcaster
/usr/bin/StreamingLoadTool
/usr/bin/createuserstreamingdir

5. If deinstalling for good, also remove the relevant entries in
/etc/hostconfig
namely,
QTSSWEBADMIN=-YES-
QTSSRUNSERVER=-YES-