It seems that he only needs to wait for the green card to come. When he
entered US, the IO should have stamped his passport with GC, and his
passport can serve as a GC. The actual GC may come in 2-6 weeks.
CR2 is a conditional GC for 2 years. He can apply for a non-conditional one
after this. http://www.fianceandspousevisa.com/Visa_FAQ.html
