Trump should do what he should have done his first day in office. He should declare the Obama-administration guidance null and void. Having sworn to preserve, protect, and defend the Constitution, he could explain that, while he would certainly execute any accommodations Congress enacts for “dreamers,” the president has no authority to confer positive legal benefits — such as work permits — on aliens. Trump could remind the public that President Obama himself publicly admitted he did not have the constitutional power to do what DACA does. Consequently, it makes sense for Trump to end the program now rather than continue on an unconstitutional course that the courts would inevitably invalidate. You don’t fix a problem by persisting in a lawless holding pattern.
The president could then explain how prosecutorial discretion legitimately functions, and how it would be exercised in favor of the dreamers.