I having a problem a hair mesh I've meshed few days ago. It has odd shading on its side, and I have no idea how to remove them. I've used milkshape 3d to model it.

P.S I've also tried the demon tool, but it only makes it worse.

Besides stating the obvious that the mesh is borked, do you have a back up of prior to having the issue?
This kind of thing does happen and sometimes without finding the culprit which is why I always save under a different name after certain changes to a mesh.

that particular part is double layered, you prolly got it from a sims 2 mesh?(sims 3 hair meshes are not double layered.)
You need to delete the back faces by doing the following.
Go to right side view
Use the select button and at its options choose faces and tick the box hide back faces.
Select the side of the hair and then hide the faces after they are selected.
untick the hidebackfaces option and select again the side of the hair.
Unselect the area that doesn't give any problems then delete the problem faces.
Then unhide all and realligne the normals on the part with Demon's tools

Thanks Base! It works now :D