Tyler, to get the yarn through the backer rod, take a big sewing needle and run it all the way through. You now have a hole in your backer rod. Through this hole, pass some fishing line, and then make a loop with the fishing line, and pass it back through the hole. You should now have a loop of fishing line on one side of the backer rod. Put your yarn (both colors) through the loop and pull the loop (with the yarn in it) through the backer rod. Trim the yarn. The needle is only used to make the hole.