How to set Remote Pan Id to Router and register with Cordinator?

I have one Coordinator with API mode and multiple Routers with API mode. Coordinator can discover routers and can communicate with each other. Now I want to change PanId of all the Zigbee Devices. So I am sending Remote AT command to change PAN ID to all Routers using Coordinator and then updating Coordinator panId using AT command of updating self pan Id. After doing this All Routers and Coordinator have new PAN Id but now coordinator is not able to discover routers, but routers can discover Coordinator. In my case i can not discover using routers so is there any other way to achieve this. I just want to change PanId of all the devices using coordinator only.

Note: I am using XBee S2C Modules for both coordinator and Router