General:
* Severed
* Amputated
* Mutilated
* Cut apart
* Torn apart
* Sliced
* Chopped
* Dissected
More specific:
* Decapitated (for removing the head)
* Quartered (for cutting into four parts)
* 肢解 (肢解 is the Chinese word for dismemberment, and it can be used to refer to the act of dismemberment in a more visceral way)
It's important to choose the word that best fits the specific situation and tone of your writing. For example, "severed" might be appropriate for a medical context, while "mutilated" could be used to describe a gruesome scene.