They should treat the UK the same as any other independent foreign country, which is what they voted for.
This means no special deals, but no punitive measures either.
um u ddo realize that Germany has just sealed the deal with China and US? They pretty much don't care if they lose some money on UK as long as that teaches the lection to other EU countries... I mean if EU can punish and destroy UK, what would it do to Polnd, Hungary, or any other less significant country...