So you need :
- Mechanical pencil refill container (only the cap would be OK)
- Scissors or knife
- Useless USB thing
Step 1: Prepping the Cap
Cut off the two little wings.
Step 2: Put the Heat On!
You may also clean the oven because you will obviously be taking picture further down the process and you don't want anybody on the internet to see how dirty is your oven.
Wait until the element is almost red. But red is fine. Unless you don't like red. But the element won't turn blue, even if it's you favorite color.
Step 3: Smoothening and Shaping
You can do this with your bare finger, but I don't recommend it since IT BURNS!!!
Wait until the plastic begin to "smoothen" and then you force it onto your useless USB thing.
You will have to repeat the "heating + forcing" process a couple of time before it fits well.
Once you're done, it may be a little too thight in the beginning but it loosen after a couple of insert/remove. Now it's all personnal preferences, since some prefers it real thight.