Quiet nice instructions… but you are missing a few important steps which are necessary to avoid damage:
1) You forget to mention the 3rd screw at the entry of the battery compartment.. in your picture of step 8 it is allready loose. It is not possible to remove the back panel without loosening of that screw.
2) It is much easier to remove the back panel, if you lift up the top panel, therefor you should loosen the two J00 screws under the internal flash.
3) You forget to mention that there needs to be a screw removed at the “dioptre correction wheel”, therefor the central small rubber patch needs to be removed with tweezers, then the underlying J00 can be unscrewed and the “dioptre correction wheel” removed.
4) Once the back panel has then carefully be loosened with a plastic opening tool you should be able to remove an additional screw of the eyepiece (right side), so that the eyepiece cover can be lift off, and then the backpanel is much easier to be removed.
Look for youtube “Dissasembly A6000”!