I struggled a little also as it is very tight in there. I was able to get it through from the middle (coming from the back of the opening) towards the driver side as you move towards the windshield. I used a small wire fish to get it through....so keep trying. It helps to use a trim pry bar to full down the headliner near the windshield also.
If you can remove the visor stay it looks like it would be much easier...but I found that rivet behind the little cover impossible to get out...so I did it with out removing the visor stay...which added to the challenge