Procedure
Article 142 of the constitution states that the Council of Representatives shall form a committee from its members "representing the principal components of the Iraqi society", which should present proposed amendments to the Council within four months. The amendment package shall be voted on as a whole by the Council, and if it is passed, put to a referendum, which shall pass if approved by a majority of voters and is not rejected by a two-thirds majority in three or more governorates. The conditions for this referendum are the same as the conditions for the original ratification referendum.
The constitution can also be amended by a general procedure, laid down in Article 126, which requires a two-thirds approval in the Council of Ministers, followed by approval by a simple majority in a referendum.
Read more about this topic: Amendment To The Constitution Of Iraq