Thoughts from Vatican 1:
The right meaning of the expressions ‘living tradition,’ ‘living Magisterium,’ ‘hermeneutic of continuity,’ and ‘development of doctrine’ includes the truth that whatever new insights may be expressed regarding the deposit of faith, nevertheless they cannot be contrary to what the Church has always proposed in the same dogma, in the same sense, and in the same meaning (see First Vatican Council, Dei Filius, sess. 3, c. 4: “in eodem dogmate, eodem sensu, eademque sententia”).
If anyone shall assert it to be possible that sometimes, according to the progress of knowledge, a sense is to be given to doctrines propounded by the Church different from that which the Church has understood and understands; let him be anathema (Dei Filius c. 4).
For the Holy Spirit was promised to the successors of Peter not so that they might, by his revelation, make known some new doctrine, but that, by his assistance, they might religiously guard and faithfully expound the revelation or deposit of faith transmitted by the apostles (Pastor Aeternus, 4.6).
---
V2 fails in this regard, as they used a "pastoral" approach to re-define dogma, because the Modernists knew they could not define error, nor could they infallibly teach error, or change Tradition/Revelation. So the "pastoral" novelty was used to confuse, contradict and get around the clearly defined rules from Vatican 1.
Vatican 1 clearly tells us that both the solemn magisterium and the ordinary magisterium are universal, in the sense that they don't change. Divine Truths are universally (i.e. always and everywhere) true, because God is always and everywhere unchanging. In the same way, Tradition cannot change because what was "handed down" is the same for all times, all peoples, and all nations. God's truths don't change and every generation must abide by the same truths and rules.
V2 cannot be binding in any way, for that would be a gross contradiction. How can a pastoral, novel, non-doctrinal, non-infallible council have authority to change prior doctrines, prior infallible statements, and prior papal authority? It cannot, in any way, shape or form.
The pope cannot change Tradition anymore than he can invent new doctrines.