Good evening mate,
Firstly, iFixit doesn't do replacements as 1) They don't sell the part and 2) They are not a repair shop.
As for how to fix a shaky camera, I don't have much in the way of that. Can i just ask, were you using it while doing something rough? (E.G driving a stiff car or a bike) If you were then apple did release a statement saying this could happen as a result of that and that they didn't want anything to do with it if you did, which i find unfortunate.
If not though, then that's a consumer law thing (or whatever the equivalent is if your not in Australia) or a visit to the "geniuses" at Apple because %#*!^@ they will refuse to sell you that part. It's unfortunate but it's the harsh truth