A rolling program a month here a month there then a month here repeat as necessary.
One well see a lot of self deporting taking place.
The other thing that need attention is following up on visa overstays. There is really no legal avenue for these people, they can just be rounded up and sent home. I have seen figures that suggest that one third of the total are visa overstays. Ferret Sessions said that it will be “next year though” before their “new” computer system is operational so we can actually start the process of rounding up overstays. Now isn’t that just like our government?
There is also the issue of some of the “country’s of origin” refusing to take their citizens back. China is one.