how do i lower the rear sun visor on the rear window shield

hello i just bought a 1990 735il and i dont know how to lower the sun visor in the rear can some one help please i cant find it any where in the manual

If it's the electric rear sunshade, there's a switch...somewhere...not sure where as my car has the manual sun shade, in which is just a slight tug out and back in. If it has been pulled too far out, you'll have to take the rear parcel shelf out and re-roll it and reset the spring so it will go back in.