birchmore

I have an octagonal shaped room (silo, 3 stories tall) and I need to build a stair case along the outer wall, following the shape of the octagon, with winders in the corners. What is the best way to go about doing this? I can't seem to figure out how to get the angles correct, the railings to work, get it to create winders on the corners, or get it tight to the wall.