Replace defective MacBook Logic Board
I noticed step 32 shows a Heat Sink for a DG board, but the remaining steps show a different type. Didn't affect the teardown, though.
MacBook Pro 15" Retina (Mid 2014) Logic Boards had either dual graphics processors or a single integrated graphics processor. The heat sinks for these two models are not interchangeable. If you are replacing your logic board with one that has different graphics processors you may need to replace the heat sink as well. Not sure what logic board your laptop has? Use ID your Mac to identify your laptop.