We need to secure our borders first and foremost. That will take time.
Any illegal alien arrested in the meantime for committing a high misdemeanor or felony get a ticket on the first plane out of the country.
Once the borders are secure and in good order and we have a rational immigration policy, read NO immigration from anywhere for any reason for a period of time, we can deal with illegals still present.
I could get on board a program of them turning themselves in if they have no criminal charges (other than entry), have a job, and a place to live. They can be vetted, swear allegiance to America, agree to learning the language (if they haven't already done that) and after a period of time, become citizens.