To add a multi-engine piston rating to the candidate license, he should have completed at least :
-hold a License of Private Pilot (PPL)
-valid ELP (level 4 minimum)
-70 hours as PIC on an aircraft
The training in details:
The candidate will follow a 12-hour theoretical training and will take a general knowlegde test of the aircraft used (Diamond DA42 Twinstar).
As far as the practical part is concerned, you will have minimum 6 hours training in dual command flight.