Fill Form 109 in triplicate in Original for termination for transfer. For getting transfer your Principal must agree and if you are in second/third year of articleship then you first need to take permission from ICAI requesting them to grant you transfer. ICAI will give permission as per the grounds mentioned in transfer rules. So make sure your reason for transfer is one among the rules. After ICAI approval, you can sent above Form to ICAI. One copy to your conerned Regional Office, One to your Principal and the last copy with you. After joining at other firm, again fill Form 102, 103 and execute the deed in stamp paper. Send these forms to same concerned Regional office, if you joining in that RO limits.