You just have to DELETE the Files from ReShade and teh ones it created.
For an DX9 game this would be the d3d9.dll, for DX10 and 11 Games that would be dxgi.dll or d3d11.dll.
Now, if you just delete the mentioned DLL´s, the game WONT load reshade anymore and therefore it is not in the game anymore.
The steps explained in the Link you provided are the right ones.
So, if you did what was in the Tutorial, it should be Removed.