Couchbase upgrade with XDCR

I inherited a few CB clusters. They are running version 4.6.1. We need to upgrade to version 5.5. Each cluster has setup XDCR to another site running v4.6.1. (Primary(v4.6.1) -> Secondary (v4.6.1) (via XDCR))

  1. What is the general procedure to upgrade in this setup?
    Should I upgrade the secondary cluster to 5.5 first before upgrading the primary cluster? (Primary (v4.6.1) -> Secondary(v5.5)
  2. Can I setup a new XDCR cluster running v5.5 and have replication go from primary cluster v4.6.1 to new cluster v5.5? Then move connections to the new Secondary and build a new XDCR cluster as secondary off the (v5.5) cluster?
    Primary (v4.6.1)
    -> old Secondary (v4.6.1)
    -> new Secondary (v5.5)
    Move connections to new v5.5
    new Primary(v5.5) -> new Secondary(v5.5)

Thank you