How to update settingvalue in nodesettings table

I need to update SettingValue in NodeSettings Table for one of the node, I see an option to create a new one but not to update the existing one.

prop = {
        "NodeID": nodeid,
        "SettingName": "ROSNMPCredentialID",
        "SettingValue": value
      }
      result = swis.create("Orion.NodeSettings", **prop)

I am using the above code to create, kindly help me in updating the existing node.

Thanks

Goutham