>  Do we still need a complex import plan described for this, with revert plan etc?

Yes, if you want the data you have already imported to stay in OSM rather than be reverted.

You were told what you need to do via the comments to  https://www.openstreetmap.org/user/YerevanTreeMap/diary/405949 .  To ignore those comments shows disrespect to the rest of the OSM community.
