It used to be open to tours but ever since 9/11, they shut that whole thing down. Now it's done more on personal requests but you literally have to sign waivers never to put these photos on social media nor does the Golden Gate Bridge take responsibility if I say jump off the bridge at the top of the tower. Wish I could get others to go up there but just no deal. Honestly I wish I even had more lenses up there like a zoom cause it sort of sucks to only have 2 focal lengths.
Just make sure you have a tripod of course and have spare steel wool. You might have to do a couple of tries to get a good photo and mostly cause of the spinning of the wool and not so much of the camera. Also shoot in dark areas. Any ambient light takes way from the sparks. And also do like 10-15 second exposures. Anything longer takes away from the fire. Shoot lower ISO and shoot closed aperture like at f/12-30.
My favorite ones. I haven't done one almost since then.