After changing my AMD Radeon HD graphic card again, and seeing so many complains about the MacBook Pro 2011 issue online, I decided to plan to make the my MacBook only work with Intel HD 3000 graphics no matter what, to avoid the amd discrete graphics from ever overheating and failing again. I saw so many suggestions online about this, but I haven't found a real solution if the AMD is still working, and it needs to be disabled all the time no matter the application running. Please, I need suggestions. I don't want this AND graphics to fail on me again, if I keep on using it or in automatic graphics switching. Thanks.
The only walk-around, that works is described here: How to disable discrete graphics card and use only integrated graphics MacBook Pro Early 2011?. In short: remove kernel drivers for the discrete gfx card. It will make the MacOs work in the fallback mode without 3d acceleration.
To control the brightness of your screen, I recommend to use: brightness slider. Because, the standard way of changing screen brightness will not work.
ps. The only way, I know, is to overheat your Mac as suggested here and use gfxstatus to force MacOS to use the integreted gfx. Still, MacOS might switch back to discrete gfx for some applications.
If you want to change OS, check this question: Can I use Linux in a 2011 Macbook Pro with a defective discrete GPU?
If anyone is still looking for ways to do this, please check out this MacRumors forum post.
I followed the steps and my 15" MacBook Pro 2011 (with a failed discrete AMD graphic card) is working perfectly using only its Integrated Graphic.