First Lease Agreement As A Landlord Questions

[Ben Rahlf]

My wife and I are under contract for our first duplex. We'll be moving into one side and there is a tenant on the other side. We'd like to of course keep the current tenant for at least the first year while we fix up the other side. He's on a month to month with the current owner. My question is once we close on the duplex and it's officially ours how do we go about setting up a new lease? Knock on his door and just start a conversation? 

Maybe I'm overthinking it but what is this process supposed to look like?