That is not an easy one. I have done it a few dozen times and I always manage to scratch up my freshly painted backing plates, I guess there is a lesson there!
I use a modified (head ground down) brake tool used on regular drum brakes. It kind of looks like a double ended screwdriver. One end removes springs and the other has a little scoop in it that I use to grab the end of the brake spring. I use it to wind the spring around to get the "hook" in place.
This and a lot of patients usually gets the job done.
Good Luck with your brakes,
Chris