“I agree, issue a decree of excommunication for all of their Clergy and adherents,...”
Since when did holding the same beliefs as and worshiping God in the same way your ancestors did, become an excommunicable offense?
I suppose you could dig up the bodies of all the Catholics who died before 1970 and hold their Canonical trial at the same time as the SSPXers. If it was good enough for Pope Liberius, it should be good enough for them.
Think of all the paper that you could save by putting all of them on the same decree. That should make all of the greenie liberals among you happy.
There are quite a few bishops, who are bastions of orthodoxy, who might be happy to preside over such a trial. Mahony, Weakland, Hunthausen, and Trautman immediately come to mind but I am sure that there are many others.
Being in a state of Abject disobedience is enough to get them excommunicated, just look at Archbishop Burke in St. Louis he excommunicated the board of Stanislaus Kotska for that very reason.
I am not a Cannon Lawyer, but he is, so I assume him to be right.