Or, as mentioned above, just hit the 3D button on the Samsung's remote.
If you want a truly seamless experience run Plex. If the Plex for Samsung client detects the words h-sbs or half-sbs in the filename, it automatically switches the TV in (& out) of SBS 3D mode.
Once you've edited the filenames of all your 3D files, its completely automatic with no manual intervention needed (just like Bluray 3D).
Cool! Is plex for samsung an app available for the Smart TV ranges?