Great design by timrbsnow.
This model has an design if it's waiting to go to action.

But i like motion. So i used the original files (http://www.thingiverse.com/thing:1069981) to create legs that are flexed. This gives more dynamic to this nice ATAT.

I adjusted the base file, so the leg pins are a little longer.

The base has longer pins. Fit the legs. The pins will sticking out of the legs. And use a welding torch to heat the pins, the will melt and this gives a solid fixture to the base. When the material is cooling down. Position the legs , like you desire.

The headpiece can be adjusted as well. Heat the triangulaire part, just enough to make the part a little flexible. Push the head into the body and position it as you like.

i used meshmixer to adjust the legs, sketchup to make the pins of the body larger.
And 3D builder to make the parts manifold. Meshmixer can do this to, but sometimes the end result is not as nice as i wanted to be.