The repair will not be easy. By the looks of it, you will need to [guide|52955|tear it down completely|new_window=true] (this is for Gen1, but Gen2 will likely be similar) using complex tools since the Apple Pencils are sealed shut permanently. I am currently on mobile data so I can't watch it, but I have found this [link|https://www.youtube.com/watch?v=yqh6gE-aO4M|video|new_window=true] that seems to go into the procedure.
You may need to buy a new plastic body since you might have to cut into it to be able to repair it.