Divide flange into 4 parts

Hello all,

I am trying to find the best way this flange can be divided into four parts, so in the real world, those four parts can be welded together to look exactly like the model, with the corners having a 45 degree miter. The attachment below was made without using sheet metal techniques and there's a face intersection that won't allow featureworks to run fully. I figured I'd remake it anyway, since I just need help on the methodology but if this doesn't pose a problem to you, then feel free to use the model.

I'm still new to sheet metal processes so please, pardon my inexperience if I can't fully answer your replies if you need more details.

SolidworksSheet Metal