@jkane ECM and or SQL? From what version to and from? The process has been steadily getting better. I moved the sql dbs from my old sql to the new one and just did the install in 21.x and it worked. If you are changing the SQL location there is the manual updating of the Astria_Host database CompanyInstance table that does not get updated by rerunning the install wizard.
Going from 21 to 22 I installed the EclipseServerSetup and it upgraded itself and downloaded and installed all of the other installs. It is possible I never had to remove the old ones in the past.
Per @MikeGross’s advice make copies of all of the .config files in all of the Eclipse folders. I also went thru the ECM server config wizard and took screen shots.