Clean out the notch carefully with a small chisel all around the edge.

Slice off any remnants of face wood left on the braces with your small chisel. Use both hands to guide the chisel and make small controlled slicing cuts. Always push away from the face edge or parallel to it. Do not push toward the face or you might slip and be sorry. In between the braces the face should cut off clean. The edge of the face can be squared off with your small chisel.