Order them to appear and then order the US Marshals to place them under arrest for contempt of court and make sure you put them in with the general and mostly illegal prison population.
This is typical of the way Obama does anything. Just have some agency ignore the law and the courts and go its merry way, thereby creating instant precedent and defacto “legislation” for his policies.
That would be so ‘just’!
Oh well, at least he’s bringing them before his court for a dressing down.