Step 1. Close the borders as much as possible.
Everyone loves that step. Very popular one that.
Step 2. There will be some sort of amnesty for illegals currently in the US. There is no way around it. I like the idea of a financial penalty ($1,000 per person and a background check?), then becoming a documented worker on the eventual path to citizenship.
Step 2 is the proverbial 3rd rail in this debate though. No one likes it. No one will bring it up as a serious policy consideration. But without both steps, there is no way we will solve the illegal immigrant problem in our lifetimes. We could do step 1, and then wait until all the current illegals die from natural causes. I guess that would be an alternative step 2. But I don't think that one has much legs either.