In all the videos I've found including yours I couldn't find exactly same model as g551jw. All those videos have thinner models and it looks so easy to open it, but in my case I wasn't able to do it. Maybe anyone has pictures or a video of opening g551jw or some thoughts what I'm doing wrong.
1) I removed all the visible screws from the back of laptop
2) With plastic card I tried to open laptop, but as shown above in the picture(red circles), I wasn't able to loosen the parts near monitor and I didn't want to use force.
Any help will be appreciated, Thanks.