With your poles clear of old cord, push the the threader through the pole aperture. It should glide easily and once the threader is poking out the other end pull the threader through gently. Remember if this is difficult then you probably got too much sticky tape. Once through pull the threader through and continue to thread all the other poles.
Being frugal I use up the old elastic cord. The old cord can be used for lanyards and neck cords. I hung all my USB storage sticks up of the old cord.