Edit Bend Angle

This is probably a simple question for those experienced with SolidWorks sheet metal.  I have a very simple sheet metal part that has a single down 90 bend.  I would like to edit that bend but the bend angle is greyed out in the base bend feature and I don't find it called out anywhere else.  Can someone tell me how to change the down 90 to say a down 85?

Thanks,

Steve

SolidworksSheet Metal