Just take the laminate trimming bit into the corner. It won't get right into the corner, but will leave a radius in the laminate. Use a flat file to complete the corner laminate bevel, working carefully. Always stroke the edge in a downward motion with the file. Dragging the file away from the countertop substrate (plywood or novoply) will chip the top layer of the laminate. Some fine sandpaper or a very fine file will smooth the beveled laminate edge.