CR7 won't leave. He will see out his contract, I am certain about that. One among Benzema/Higuain should leave. I would prefer Higuain to stay, as Higuain at his worst >> Benzema at his worst. Alonso is getting old, and he is getting susceptible as he has shown this season. Better to offload him, get some cash rather than letting him leave for free next year. Di Maria is highly inconsistent. That being said, I would keep and use him in the rotation system. But he should not be the first choice. We need a better winger.
Among the defence, I think Albiol should leave. Carvalho is leaving. Ramos and Varane first choice. Pepe second fiddle to them and we should probably buy a good veteran defender and a good RB to replace Arbeloa, who should be offloaded as well. Looks like, Madrid might exercise the buy back clause in Carvajal's
contract at Leverkusen. He was a good prospect at RM B and shouldn't have been loaned out in the first place, with basically no RB right now.
Modric is gaining confidence and with the recent minutes he has seen under his belt, he is looking quite sublime actually. Has that creative touch. So a pairing of Modric-Khedira in the long run may be good. But, I want to see Juve's Vidal/Pogba, City's Silva, and one of Falcao/Cavani next season.
Of course, more additions are need to be made, but this is where I am right now.
[EDIT] Oh and Kaka should leave. Not doing us any good by paying him millions and make him sit on the bench or the stands or not doing him any good either. The WC in Brazil is a year away, I think he should fancy a spot in the squad at least, by going somewhere where he will get many minutes to play.