This project fairly straight forward and only needs a few supplies:

Paracord
Headphones
Heat-Shrink Tubing
Solding Iron (you can get away with a lighter)

Step 1: Cut Headphones/Stringing the Paracord

This step may seem heartbreaking but you'll have to cut the headphone wire in three places. Around 1" before the three wires intersect is where you'll cut and strip the 3 wires.

Once you have the 3 separate strands of wires apart, you'll need to cut paracord that's the same length of the wire.

Next remove the inner strands of the paracord, leaving just the outershell

Finally, string the headphone wire through the outer shell of the paracord, this can be be done by "scrunching" up the paracord and then extending it over the wire. This may sound strange so refer to the video on the first step if you're confused!

Step 2: Soldering the Headphones Back Together

Once the wire has been strung with the paracord, place some heat shrink tubing on the wire so you can seal up the soldering joints a littler later.

After stripping the headphone wire, you should see 2 wires all wrapped in colored cotton fiber. To reattach the wires together, you first should physically twist the wires together: and then burn off the cotton fiber with a lighter:

Once all wires are twisted and burned together, test out the headphones... do they work?
If so then awesome! if not, you'll need to whip out the soldering iron and solder the wires together, that should do the trick.

Then add some vinyl tape around each wire to reinsulate them and seal everything up with the heat shrink tubing!

Step 3: Repeat Until Finished!

Repeat the previous step for the two other wires, feel free to mis-match colors!

Mine turned out pretty well, definitely won't be tangling any time soon!

Let me know if you have any questions!