
It seems that the legal team of the three are going to take this thing to the ICJ. I am not entirely convinced that they can as the ICJ is generally a State against State deal.
Achmad Michdan of the legal team has said they are going to send a letter to the "International Court". I am guessing that this is the International Court of Justice (ICJ).
My guess is based on a Kompas Newspaper report (in Indonesian). However, a letter would seem to be wasted on the ICJ. It would make more sense to send a letter to a UN organ that dealt with human rights, such as the Human Rights Council.
It seems that the legal teams complaint is that the Constitutional Court of Indonesia does not take into account that the prescribed method of execution in Islam is beheading. I need to find out some more information on this.
I will check it out later in the morning and add a postscript if, and when, I find out something.
Thanks to Calupict for pointing me in this direction.