Samsung Galaxy Note 4 - Manual (Page 11)

Getting started
11
Removing the S Pen
When you remove the S Pen from the slot, the device launches Action memo or displays the
air command features depending on the S Pen detachment option setting.
To change the setting, open the All apps screen and tap Settings
→ S Pen →
Detachment options.
Replacing the S Pen nib
If the nib is dull, replace it with a new one.
1
Firmly hold the nib with the tweezers and remove it.