Clear out that hideous automated face, to make a hole, and rebuild the topology by hand. Connect two vertices and press F to join them (creates an edge). Which two vertices to select? Well, just follow the lines. Then after you've connected the vertices in one direction, fill all triangles with faces. Then, connect the vertices in the other direction, this time using J. Then merge the very close vertices, in the intersections that the joining (J) operation created, and then move some verts around, selecting one vert at a time and pressing "g" twice, to move the selected vertice along the edges - this is to even out the triangles.
And then turn off auto smooth!
It's not the perfect result, but it took me like 5 minutes. You can spend more time adjusting each vert (with Auto-Smooth turned back on), and then maybe smooth in Sculpt, or use a Shrinkwrap from a piece of the other leg, scaled by -1.