Since Nokia abandon N9 and Harmattan, i think there's no other way for us to get a delicate service from Nokia Care.
I broke my USB door twice, when i say it's for N9, they say they don't have any parts of N9, if i want, i have to wait a month or two; then, enough said; OK, i want buy a Lumia 800 USB door, and voila....it's available in all colours!.
There are many online sellers who sell N9 parts, then find a tutorial videos and buy some tools, some other way it makes you more caring and loving your N9 afterward