It was kinda simple, I thought it would be a mess.
did this:
Also:
Sync all your databases.
Uncheck iCloud sync from preference.
Unregister DevonThink
External drive.
copy the folder where all your databases are in, then paste it to the external drive then when you have installed a fresh DT just drag the folder containing the databases and drop it where the DT databases reside.
Open each database then check sync from preference .
Done.
Plus for good measure I recorded my preferences(screen recorded), some settings didn’t transferred.
I don’t get why DevonThink doesn’t stick a thread guiding ppl step by step how to properly do this. its simple but since DevonThink is complex we automatically assume this task would be difficult.