Hi Chee Wong,
You are correct, but you need to type reboot once you have typed "set scg ip x.x.x.x"
where x.x.x.x is the SZ IP address.
Here is a YouTube video that will show you the process:
Here is an...
The following article explains how to convert an AP into Unleashed(Standalone mode)
The following link is the firmware required to flash the Access point to standalone mode