I use half a popsicle stick as a punch to get it through the hole, but it's short lived. Some kind of hardwood wood be better. Perhaps a wedge for an axe or hammer handle, if you have a spare around there.
I have also driven a toothpick in there above the spring to hold the wedge spring hook down and then broke the toothpick off, so it won't be in the way. And drive the broken tip back out with the wedge.