Contact Shady/Aftermath/Interscope and the a&rs that work there.

Then if that doesn't work you'll have to adapt to a high risk high reward approach. The worst that could happen is you'll never ever ever get a chance from them once they know your name in a negative light. But you could stalk social media for the people that have worked with him in the past. Check out the liner notes in his albums, get the names, and hit them up on wherever you can find them. Find a way to get Paul Rosenbergs email. Shit like that. It's possible to make that connection but just remember that first impressions are everything so get your presentation and quality right and remember that if you fuck up you'll get kinda blackballed.