The task you want to do is quite simple to be honest, but the simplicity really depends on how much knowledge you have of the tools needed to do this:
· TSRW or
CTU · Milkshape
· Blender (this one is sometimes optional)
· Image manipulation software, like Photoshop or Gimp
· Mesh Toolkit
You might want to start by reading
this, and then search even more detailed or in-depth tutorials on each particular step.