I guess you haven't checked the manuals ??
Its simple In settings go to security << mobile tracker << activate it and set a password and set two Nos (recipients )
Then a warning might appear. just accept it
Now is done whenever you or any anyone change the sim card a sms containing IEMI no of your phone and mobile no. of the sim inserted will be sent to the two nos. you that have set
You may try it
But the sms will not be sent if you have inserted another sim which is inactive or which has Zer0 balance