Ask and ye shall receive...
We specifically command each and every patriarch, administrator, and all other persons or whatever ecclesiastical dignity they may be, be they even cardinals of the Holy Roman Church, or possessed of any other rank or pre-eminence, (In other words, the whole church)
and We order them in virtue of holy obedience (sin of disobedience is in play here)
to chant or to read the Mass according to the rite and manner and norm herewith laid down by Us (Pope orders the Church to use ONLY his missal)
and, hereafter, to discontinue and completely discard all other rubrics and rites of other missals, however ancient, which they have customarily followed; and they must not in celebrating Mass presume to introduce any ceremonies or recite any prayers other than those contained in this Missal.
(the novus ordo introduced new ceremonies and new prayers, and also deleted ones from the 1962 missal. All of this is not allowed, is illegal and sinful).