Sounds easy but I think there is a great effort required even in this. They are not all on gvmnt assistance despite what some think.
No one is proposing going door to door and yanking people out of homes. There are quite a few on government assistance and quite a few that are opening up bank accounts (thank you Bank of America), applying for drivers licenses, etc. that can be reported and deported. Doctors offices and our hospitals and emergency rooms are full of illegals. Having worked in the medical field I found it extremely frustrating to have to register someone or hand over medical records to someone who was given "free" and costly medical care and the only thing that they can produce is a damn Matricula Consular card as identification.
As was stated early by other posters, cut off the benefits, cut off the "freebies" and they will self deport.
Another poster also stated that there should be a moratorium on immigration into this country and I agree wholeheartedly.
All of these suggested methods, while not perfect, do not involve going door to door and yanking people out of their homes as the DEMS would scare you into believing.