Q. 1. Can you tell me, how does the Code of Canon Law get amended?
A. 1. Only the Pope has the authority to amend the Code of Canon Law as can be seen from the following events:
On 25 January 1983, with the Apostolic Constitution Sacrae disciplinae leges John Paul II promulgated the current Code of Canon Law for all members of the Catholic Church who belonged to the Latin Church. It entered into force the first Sunday of the following Advent, which was 27 November 1983. In the Apostolic Constitution, the Pope described the new Code as "the last document of Vatican II".
In 1998 Pope John Paul II issued the motu proprio Ad Tuendam Fidem, which amended two canons (750 and 1371) of the 1983 Code of Canon Law and two canons (598 and 1436) of the 1990 Code of Canons of the Eastern Churches, so as to add "new norms which expressly impose the obligation of upholding truths proposed in a definitive way by the Magisterium of the Church, and which also establish related canonical sanctions."
On December 15, 2009, Pope Benedict XVI issued the motu proprio Omnium in Mentem, which amended five canons (1008, 1009, 1086, 1117, 1124) of the 1983 Code of Canon Law clarifying that, among those in Holy Orders, only bishops and priests received the power and mission to act in the person of Christ the Head while deacons obtained the faculty to exercise the diakonias of service, Word, and charity. The amendments also removed formal defection from the Catholic faith as excusing Catholics from the canonical form of marriage.
On 15 August 2015, Pope Francis issued the motu proprio Mitis Iudex Dominus Iesus reforming the matrimonial nullity trial processes of the 1983 Code of Canon Law, dealing with declaring the nullity of marriage. The document was made public on 8 September 2015.
While there have been many vernacular translations of the Code, only the original Latin text has the force of law.