Where does it allow succession, or state the procedures for succession?
You've got it backwards. The Federal Government is presumed to have been intentionally denied any powers not delegated to it by the states in the text of the US Constitution. Any powers not delegated to it, therefore, have been reserved by the states to themselves as part of their original sovereign power.
In case at some point in the future the above principle might become unclear to anyone, the Founders insisted that one of the ten articles of the Bill of Rights laid it out in no uncertain terms, i.e., the Tenth Amendment. Read it.
Therefore, since the States never delegated away the sovereign power of self-determination, they retain said power, which they only held in dormancy for as long as the Federal Government continued to exercise its delegated powers "in such a form as to them shall seem most likely to effect their safety and happiness."
They had just fought a long and arduous war with England over this very principle, i.e., the right of secession. Therefore it's the height of absurdity to suggest they would immediately thereafter engage in a pact with a newly established central power which denied that very principle.
