How to remove these marks?
View attachment 765516
I can think of three methods. The first two need you to take a VERY close look at the diffuse map for the limbs, and see if the blemishes are there.
a) If the spots are there, then photoshop, VERY carefully, to remove them.
b) If they are not in the diffuse texture, then check the bump, specular and normal maps for any hints that they are the ones to blame. In that case, lower bump, specular and normal map values in the surfaces tab, or simply use a different bump, normal, or specular map (or any combination of those), from another character with the same UVs, that is smoother than the ones currently in use.
c) If it's not related to any of the mapping, then it's a geometry and/or lighting glitch. Subdividing the figure one step higher, if the hardware allows it could work, and/or play with any specular light values, angles and distances.
If none of the above works, then... photoshopping the final render may be the only option.