How best to secede from a state...

How best to secede from a state.  I've been amused by, but have mostly ignored, the various votes of different places to secede from the state they're in.  For instance, several counties in California and Colorado have voted to secede and form a new state, free of the raging progressive politics their citizens dislike.  I know that it is incredibly unlikely that they could ever succeed in their secession, not least because they have to have the approval of both the state they're leaving and the U.S. Congress.

But Eugene Kontorovich, writing at the Volokh Conspiracy, points out that there is another way: secede and join another, already existing state.  While there is clear governing law for forming a new state, things aren't nearly as clear-cut for a transfer of land from one state to another.  The state being joined need not even be adjacent to the new piece (look at Michigan!).

Maybe Jamul could secede and join, say, South Dakota?