When you arrive at T2, please walk to collect your luggages firstly and then head to the customs and immigrations area. Ps: you don't have to accept customs and immigrations inspection, so just please tell the staff your situation to make a transit in T3.

And then, please follow the directions to the Gate 11 on the 1st Floor, where you could catch a free bus to arrive at the departure hall of T3. Finally, please check in your flight to Frankfurt.

Thanks for u r reply.