nikon D3/D3s hot shoe screw loose-need to dissasemble. back focus nikon software

[super steel]

I came here because of this post
https://www.eevblog.com/forum/reviews/nikon-d3-dslr-partial-teardown-and-attempt-of-repair/25/

last year I payed for a hot shoe repair. the hot shoe became loose on one side. I went back to the lab they said "you work with the camera, it happens, pay up" I also relaized 2 screws were missing from the bottom at the rear bottom left and right panel near the corners of the body. they installed 2 screws "on the house" WOW! now I can sleep well.
I dont want to pay up. not sure how much warranty there is but this is not something that should happen, even for a pro photographer. the camera is a d3s btw.

I saw this video


I will do the repair to tighten the screw/s myself. my question are
1-in the video, he removed the back panel first. is this necessary to remove the top part/hot shoe?
2-I counted 6 screws around the body just to remove the top plate, yes?
3-having a problem with lenses reading error with it not reading aperture. if I twist the lens slightly it will register and shoot fine. the guy said aperture mechanism isnt reading the lens to be "stopped down"

first time here. not sure if someone can help. any help, much appreciated.
if someone can recommend a video for a top plate teardown or even fixing aperture mechanism, I would extremely appreciate it (d3/d3s mostly the same-I have both)

as well Im wondering where one could fix a back focus issue with some software. I also payed the lab to repair that. it came back 6 months later. I work with this cameras and quite a poor photographer so dont have extra money to throw for the same repair. or any repair really. I biughgt both cameras after massive use and replaced shutters/mirrors/aperture mechanisms

cheers everyone

[eKretz]

The D3 service manual is available:

http://www.fredmiranda.com/forum/topic/1253752