Apparently this is how the executions will take place:
They are due to be shot by human beings. A group of special police officers will tie each prisoner to a post in dark nightfall, just before midnight. A colleague will shine a torch onto the prisoner’s heart.
Another group of police officers will line up and fire at the target. Only some of the officers will have live ammunition, others will fire blanks so that they don’t have to face the moral consequence of guilt and blame, of knowing who fired the fatal shots.
Bali Nine: Indonesia confirms it will execute prisoners tonight ? live updates | World news | The Guardian