Rendering (opengl) in a separate thread?

Could someone walk me through the steps (via sdl calls) that will
allow opengl rendering in a separate thread?

I can see from the wiki page that user events and video calls must be
handled in the main thread:

Does this mean that SDL_SetVideoMode() must also be called from the
main thread?

If this generates the draw context that OpenGL uses, does that mean
that SDL can only be single threaded when it comes to user events and
opengl rendering? Or is there some way to detach and transfer the
draw context to new thread?