Hey!
Welcome to the planet!
Like Rob says, it really depends on what you are wanting to do. But if you are wanting to change the pose, I would assemble the two halfs of the body and then cut off, lets say the legs, where you want to reposition them, then put some putty in each of the parts that you just cut off, and then pin it with a paper clip or something, and then resculpt the ares where needed, trying to match the sculpting of the original figure. This is just a general way of doing things, if you are more specific we will be able to help you more.