Guys need advise.

Mr A is buying new car (Car 1) and selling his current car (Car 2). Mr A also will retain the registration no on Car 2 (P11) and transfer it to Car 1. Process is expected to be concluded in June.

Mr B has tendered new registration no (F11) and want to buy Car 2 by cash and use the registration no there. But he is in oversea now and will b back in Malaysia in 2017.

Questions:
Can the interchange be done since potential buyer not in Malaysia? If not mistaken now compulsory biometric right? If can be done what are the process?