(Also posted on TMP)
My added advice:
Glue -- use Ambroid ProWeld (available at most hobby shops that sell plastic models). It works perfectly on this type of plastic. Also works by capillary action (see next comment).
Assembly -- Use the guide/link provided by Extra Crispy, with this additional step -- after you have the legs in the body (loose) and the two body halves glued together, support the body with some modeling clay up to the height desired then position the legs the way you want them. Work the clay to raise or lower the legs if needed. This way you're sure the legs will all touch the table when the figure is done (and not wobble). Then apply the Ambroid glue. It comes with a built-in brush. All you have to do is brush the glue around the leg ball joint areas and the glue will pull itself in around the ball joint. As the glue takes, you still have time to adjust the body and legs to make sure all "feet" are even.