Still learning how to use blender myself, but I will try this soon,

Hope that can help some

IF you use Blender, there is a way to make normals show the direction they face, and then just opening it in Modeling View and pressing (A) then (Shift + N) should fix most normals on the object, the ones that it doesn't fix you'll have to select by hand and do (Shift + N) again, changing its settings based on if it flips them or not.

Yeah I know, Ive spent the last week trying to fix them (Not my model, just a lanky one Im trying to fix)

finally I just uploaded it anyway,

DookaDoo, Half of the normals on this are flipped the wrong way, it doesn't look great because of that