It’s a little tricky (you have to wrap around under the bridge and the path is far from clear), but it sure beats walking your bike northbound battling pedestrians. The BCU has released this video to help you figure it out.
I have used it a couple of times, and found it confusing all of those times, you are put into conflict with traffic both pedestrian and car at odd points, but with a bit more signage it might be ok. I still think they should just close the bridge to cars, and let cyclists/pedestrians take the whole thing until it’s don’t being fixed.
https://youtu.be/eKCQpLXCIzI