SB-600 - CLS Remote
To set the SB-600 to Wireless Remote mode hold the ZOOM and [-] buttons at the same time for approx 2 seconds, or until the Custom Settings mode appears.

If the Wireless Remote Mode Indicator is not shown, Press the [+] or [-] buttons until the Wireless Remote Flash Mode appears. This is indicated by the arrow on the display.

Press the MODE button to toggle between OFF and ON (set to ON), to enable the Wireless Remote Mode, then press and hold the ZOOM and [-] buttons again to exit the Custom Settings menu.
To disable Wireless Remote mode, simply repeat the procedure above, but press the MODE button to toggle the setting to OFF.

Note that when the Wireless Remote mode is active a new icon will be displayed on the LCD.
Setting the Channel
The Channel on the SB-600 must match the channel on the Master, otherwise the Remote SB-600 will not flash. To select the Channel press the MODE button until the Channel number starts blinking, then use the [+] or [-] buttons to select the required channel. Once this number matches the number set on the Master, press the MODE button to confirm.
Setting the Group
Press the MODE button until the Group starts blinking, then use the [+] or [-] buttons to select the required Group, then press the MODE button to confirm. The choice of Group is up to you. How this SB-600 will flash will now be controlled on the Master unit setting for the chosen Group, and in most cases each Remote will be set to a different Group to allow the greatest amount of flexibility and control of the scene.
Setting the Zoom
When using the SB-600 in Wireless Remote mode, the zoom setting is no longer controlled directly by the camera, and should be set manually. For coverage of larger areas a wider angle is generally more useful, but if you need to concentrate the light in a smaller area increase the zoom setting. Press the ZOOM button to advance to the next ZOOM position.
Note that if the Wide Angle Diffuser is out, the ZOOM will be fixed at 14mm. Simply retract the Wide Angle Diffuser to allow the ZOOM to be set to other positions.
All Done ...
Your SB-600 is now ready to operate as part of a CLS Group. For information about setting up CLS Speedlights, choose one of the following links:
Setting the SB-800 as a CLS Master
Setting the SB-800 as a CLS Remote
Setting the SB-900 as a CLS Master
Setting the SB-900 as a CLS REMOTE