Give the kids in school a foreign student educational visa and allow them to complete their education. Seems simple enough. As long as they are working toward a degree in a reasonable timeframe then there should be no problem. 

Give the kids with jobs a work visa and legal guest status. Not citizenship but the ability to work under some conditions. 

Give employers and government aid agencies a better version of e-verify and a mandate to use it for anyone seeking employee or government aid. 

Give businesses a guest worker program that allows foreign workers (at 120% of minimum wage or the prevailing wage for whatever business needs additional workers). 

Give foreign governments a bill for all costs associated with deporting those who can't abide by the rules.