Now the obvious step 1 is to steer away from the organicish skeletonyness of the Necrons, and got more for the look for the Portal 2 robot dudes.
Step 1: dump the torso, head and hands.
Those are the biggest offenders. The head is too clearly a skull, the torso has the ribs, the hands are too skeletal.
Now we need a new body. Either round or egg-shaped. Wooden marbles, little easter decorations, etc will work here. Cut some grooves along them and sculpt the central eye.
Cut the thigh up a bit and rebuild most of it out of thin metal rods, then slap the separated thigh plate on top.
Move the shoulder plates down so they are on the sides of the arms rather than at the top of the shoulders.
Finally, hard-wire your preferred style of gun to the wrist, and if deisred, make a manipulator hook out of the same thin rod you used for the legs.
And done.