This is so entrenched it is not going to be easy, but you must do this for the sake of your family. You may have to resort to the tactics used for younger children, a star chart and if enough stars are earned a treat at the weekend etc.
A simple bedtime routine with early warnings that it is due to begin, at 9 she will be able to bathe etc relatively well on her own, but by all means chat along with her as she does. Then maybe read or chat about something together, then tell her it is time to sleep and you will pop in later to see she is okay.
If she staarts to wail, then ignore, she is 9 not a baby, if she comes out of her room lead her back and cover her up without speaking, you have reassured her once already, this will be repetitve in the beginning but you must stand your ground. If it is term time, then you may need to inform them that she may be tired due to this new regime.
Good luck and be strong, to save your marriage.
M