Because the rope I used was only a couple of millimetres narrower than the pipe itself, it was quite hard to slide through easily, so I used a bit of ribbon to help pull it through more easily.
Once the rope was all the way the way through, I fixed on the end caps with hot glue. To make a fastening, 2 holes were drilled in the end caps and a copper jump ring was opened and fixed in place to form a loop. I did this for both ends then simply attached a lobster clasp fastening. Sadly I didn't have any copper ones so it stands out a little, but will do until I can replace it.