Sanding wood, glazing, painting

The roof overhang must be painted, how is this best done? The wood was stained about 4 years ago, it now looks dark brown. Now it is to be painted white. Does the old stain have to be sanded off before painting it white, or can it simply be painted over?

A glaze penetrates deep into the raw wood, so nothing sands off easily. My tip: clean with the black side of kitchen sponges and netrol. Google it and order it, you will have a hard time getting it outside of Schleswig-Holstein. Brilliant stuff from Norway for wood cleaning. After that it will be significantly lighter. Then apply Konsolan or similar generously twice. Karsten