The German Bishops Attacked, Pius XII Capitulated

It is widely unknown that it was under Pius XII that Bugnini and Montini changed the Canon of the Mass - which is UNTOUCHABLE -and the Rubrics of the Latin rite of the Roman liturgy. Bugnini fabricated it and Montini passed it on to the pope who agreed to it.
Bugnini himself wrote:
In the twelve years of its existence (June 28, 1948 to July 8, 1960), the commission held eighty-two meetings and worked in absolute secrecy. So secret, in fact, was their work that the publication of the Ordo Sabbati Sancti instaurati at the beginning of March 1951 caught even officials of the Congregation of Rites by surprise. The commission enjoyed the full confidence of the Pope (i.e. Pius XII), who was kept abreast of its work by Monsignor Montini and even more, on a weekly basis, by Father Bea, confessor of Pius XII. The first fruit of the commission's work was the restoration of the Easter Vigil (1951). It was a signal that the liturgy was at last launched decisively on a pastoral course. The same reforming principles were applied in 1955 to the whole of Holy Week, and in 1960, with the Code of Rubrics, to the remainder of the liturgy.

The second force operative in ensuring the coming of liturgical reform found its mature expression at Assisi (1956). This International Conference Congress on Pastoral Liturgy, was, in God's plan, a dawn announcing a resplendent day that would have no decline. Who would have predicted that three years later the greatest ecclesial event of the century, Vatican Council II, would be announced? Pope Pius XII gave a fine address. In his introduction he made a historic remark: "The Liturgical movement is a sign of the providential dispositions of God for the present time [and] of the movement of the Holy Spirit in the Church."
www.traditio.com/tradlib/piusmodern.htm