How can I wake up my xbee s2?

I am a newbee to the xbee s2 and while experimenting I set up a router in API with SM set to 4(Cyclic Sleep). Now, I cannot detect it in XCTU any more.
Is there any way I can get it to detect or change SM parameter?
I have access to an Xbee Explorer, Arduino and another XBee S2.

Please help me out of this

Your only option is to enable API mode on another module in your network and the using the type 17 remote at command API function to change your sleep command or the ST time frame.