Things that you need:
1. Empty Refill
2. Pencil Sharpner
Step 1: How to Hold Refill
Hold Refill oblique such that the side of tube facing sharpener should be upwards
Step 2: How to Sharp
Press the refill against the blade strongly and sharp just like you sharp a pencil.
Make sure that you continue to do it till you reach the end.
Do it Slowly and at the end just break the refill
And you are done to play with your spring refill during boring classes.
Thank you. Hope you liked it. Comment to express yourself.