Strip them of their titles but don't pass them on. Citeh don't deserve them but neither did their runners-up earn them. We simply don't know what would have happened had City not cheated. For example:
- Where would the players Citeh bought with dirty money have gone had they not gone to City? They may have gone to clubs that finished 3rd or 4th etc. rather than 2nd with a different outcome in League Table.
- What about the teams City beat in the cups on their way to the final? Might one of them have beaten City and then in the final beaten the team that lost the final to City?
- the whole dynamic of the Premier League would have been different and we simply don't know what would have been.
For me, the right thing is to:
- Strip them of all their trophies up to and including last season
- Leave all the competitions they won without indicating any winners with an asterisk explaining why for posterity and a reminder to future generations of the shame.
as for the main punishment, I will be surprised if they aren't expelled from the League and forced to find a league that's willing to let them join - National League North (if they'll have them) seems about right to me.