Below is a picture of a stylus with the tip installed and a replacement tip below as reference.
Note: The shape and color of a stylus may vary by notebook.
TIP REPLACEMENT INSTRUCTIONS
If you need to replace your stylus tip, you require a Replacement Tip Set. Most Replacement Tip Sets come with replacements tips and a C shape tool. For instructions of how to replace the tip of your stylus, follow the steps below.
1) Locate the C shape tool. It has a notch to allow you to grasp the end of the stylus tip.
Note: If your Replacement Tip Set does not come with a C shape tool, you can use a pair of tweezers or even your fingers instead.
2) Place the tip of the stylus in the notch and squeeze the clip to grasp the stylus tip.
3) Gently pull away from the body of the stylus to remove the tip.
Note: If the tip is completely broken off and you are not able to remove the remaining part of the tip from the stylus, you will need to replace the entire stylus.
4) Use your fingers to insert the replacement tip into the stylus. The tip should be inserted until only the larger section (approximately 1/10 of an inch or 0.3 mm) is visible.