var changeGR=new GlideRecord('change_request');

changeGR.addEncodedQuery('number=CHG0040007^ORnumber=CHG0040006'); // replace with correct change number

changeGR.query();

while(changeGR.next()){

changeGR.state='3'; // replace state value here

changeGR.update();

}

Thanks,

Dhananjay.