We need to remove 2 servers from DAG and create a new DAG

Hi,

We have 2 Exchange 2013 SP1 cu21 mailbox and client access servers

We need to remove these two exchange servers from current DAG. We need to create a new DAG and add these mailbox servers in new DAG. We also need to remove old DAG. If there is any metadata cleanup is required, kindly let me know those steps too.