How do i delete the last update with the london photo scenery but keep the land marks it looked stunning before the update?

While you can’t rollback the whole update, You don’t have to roll back the update to delete the UK 3D Photogrammy Cities and UK-Procedural Buildings if that’s what you’re looking for…
Go into Content manager and delete those two updates and see if it goes back to looking like you want.
Hope this helps if this is what you’re trying to get at…
Regards