Bleeding LS4 wheel brake hydraulic system

Does anyone have any experience of bleeding the hydraulic system that
activates the LS4's wheel brake? I have heard a suggestion that it is
necessary to unbolt the master cylinder and hold it in a vertical position
in order to expel all the air from the system. Is this really true?

Also, does anyone know whether any particular type of brake fluid is
recommended or would something off the shelf be OK?

Any hints or tips would be really helpful.

Many thanks.

David Starer