The Pope can add to, subtract from, and change Canon Law. Pope Saint John Paul II signed into effect the current Code of Canon Law in 1983. This new Code includes hundreds of changes from the older 1917 Code. Any Pope at any time can issue changes to these laws of the Church.
Is the Pope above Canon law? The answer is a qualified “Yes”. Some “laws” in the Code are direct expressions of magisterial teachings on faith and morals. These are not laws in the traditional sense, since they do not require or forbid some type of behavior. They are what I call “teaching Canons”. For example:
“Can. 749 §1. By virtue of his office, the Supreme Pontiff possesses infallibility in teaching when as the supreme pastor and teacher of all the Christian faithful, who strengthens his brothers and sisters in the faith, he proclaims by definitive act that a doctrine of faith or morals is to be held.”
The above Canon concisely states the dogma of Papal Infallibility, taught by First Vatican Council and Second Vatican Council. This type of Canon has the function of relating the doctrines of the Church to the disciplines of the Church.
The Pope cannot change or nullify the dogmas of the Magisterium. He is subject to the definitive teachings of the Church, just as any believer is subject. For each Pope is a disciple of Christ. So the Pope is NOT above those portions of Canon law which directly and correctly state definitive doctrine.
However, Canon Law does not state every teaching, nor does it necessarily need to state any teaching. The teachings of the Church are expressed in various documents of the Magisterium. Their inclusion in Canon Law is useful, but non-essential. If a Pope wished to do so, he could remove any or all of the “teaching Canons”, without harming any truth, since these teachings are all expressed in the magisterial documents of the Church. But he would still be under the authority of those teachings.
Setting aside Canons which are a direct expression of teachings on faith or morals, the remainder of the Canons are not teachings, but disciplines. These are rules, regulations, instructions, and penalties issued in order to govern the Church dispersed in the world. These disciplines are not oppressive. They are relatively few, and they are fairly easy to read and understand. The yoke of the Lord is light. In comparison, the laws of secular society, of cities, states, and nations, are far more complex, numerous, and difficult to understand. The citizen of a city is subject to the laws of the city, the state or province, and the nation. The yoke of sinful secular society is heavy and convoluted.
The Pope is above all of those Canons in the law which are per se of the law, and not of the teaching authority. The Pope holds the highest office in the teaching authority of the Church, but he is also a believer and disciple of Christ, so he is subject to that authority. There is no contradiction in this principle, since the Pope can only teach truths found in Divine Revelation (and also natural law). He does not teach from his own mind, but from the mind of Christ.
On the other hand, the temporal authority of the Church is his to administer as he sees fit. The disciplines of the Church are not truths of Divine Revelation, but judgments of the prudential order and practical decisions on how to organize the people of God. The Pope is not bound to follow those laws of the Church that are per se of the temporal authority, not the teaching authority.
Some commentators argue that the Pope must first change the law, if he wishes to do what it forbids. Not so. Whoever is above the law, need not follow the law. If he were required to change the law first, he would not be above it.
An example is found in the laws of the Church on papal conclaves. (By the way, not all laws of the Church are found in the Code of Canon law; other Church documents contain laws.) Pope Saint John Paul II established a maximum number of voting Cardinals (Cardinals under the age of 80) as 120 in the document Universi Dominici Gregis. Then he subsequently appointed more than 120 voting-age Cardinals. And he did not issue a document to change the maximum number. If a conclave occurs and more than 120 Cardinals are voting age, they may all vote. The reason is that the Pope (either Pope Saint John Paul II or one of his successors) chose to appoint more than 120 voting-age Cardinals. By doing so, he overrode the law of the Church — and he has the authority to do so.
The Pope is above the laws of the Church, except those “laws” which are merely an expression of teachings. Can the Pope be excommunicated by violating a law of the Church, whose penalty is automatic excommunication? No, he cannot. He is above the law.
The sins of apostasy, heresy, and schism teach carry the penalty of automatic excommunication under the eternal moral law as well as Canon law. But the Pope can never commit any of these sins, because the prevenient grace of God gives him the gift of a never-failing faith. (See my lengthy explanation on this point in my book: In Defense of Pope Francis.)
Therefore, the Pope can never be excommunicated. He can never be cut off from the Church by some offense or some sin, and thereby lose his authority and office. A Pope can only be removed from office by death or by resignation.
Please take a look at this list of my books and booklets, and see if any topic interests you.