which procedure to migrate SMG 23 to SMG 24?

I'm running the SLES appliance version of SMG, running 23.3.8.  I now want to replace that with SMG 24.3 running on OpenSUSE Leap.  I have the new server installed and I can access the 24.3 setup page.

Am I supposed to use the "Replace an existing Secure Messaging Gateway server" role on the SMG 24.3 Server Installation screen?

Or am I supposed to follow the procedure in the 24.3 Documentation "Migrating SMG from the Appliance to a New Server"?