My boyfirned came here on a R B1 visa which expired 2 monthes ago. How to make him legal? What if he needs to go home?

An I-485 adjustment of status to permanent residence form can only be filed by an individual who is residing in the United States. I suggest that the better course would be for you both to be married here and if he needs to return to Morocco, for him to also apply for an advance parole on form I-131. An advance parole is usually available 90 days after the entire case is filed with U.S.C.I.S. If he leaves now, his case would probably become longer and more complicated. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence