Create a Plan first and Possibly assist if needed with upgrade two Servers to Server 2012 with Exchange 2016. I have two servers, the first is a Small Bus Server that is just replicating Domain function. The second is running Server 2008 R2 Std. that is the Primary Domain Controller and hosting Exchange 2010. I want to upgrade the Small bus Server to Server 2012 R2 Essentials and also install Exchange 2016.
Then Migrate the Domain and Exchange hosting away from the second server to then upgrade it to Server 2012 R2 Essentials as well.