In a word: uck. I mean, who leaves the body parts of a warrior woman lying around? Okay, so she forged a sword from the first rays of sunlight that could kill the First, but you didn't have to scatter her!
The right leg: Faith finds it in the mine, after killing Kakistos.
The left leg:Xander finds it in the high school, after beating evil Anya.
The torso: Buffy finds it in the zoo, after beating Ripper.
The right arm:Willow finds it in the mall, after beating vampiric Tara.
The left arm:Spike finds it in the Initiative, after killing Adam.