The "top" you're likely referring to is the tip of the Apple Pencil. You remove it by unscrewing it counterclockwise.
Here's a breakdown:
- Remove any pencil case: If your Apple Pencil has a case on it, take it off first.
- Unscrew the tip: Hold the Apple Pencil firmly and unscrew the tip in a counterclockwise direction.
- It should come off easily: The tip should come off without much resistance. If it's stuck, try applying a bit more pressure, but be careful not to damage the pencil.