nds 7.62c to edir 8.7.3 upgrade

Hello, we have 6 Netware 5.1 servers w/nds 7.62c. We are about to install
edir 8.7.3. The 6 servers host our GroupWise, which is very important to
us and we want to ensure that we still have the ability to manage it after
the upgrade to edir 8.7.3.

We have no errors in nds replica and time sync. NDS is healthy.

Do we start with the server that holds the master of the root?

Do we have to update the schema first?

Do we continue to manage with ConsoleOne?

Thanks very much.
Marie