Help With S795 balance and 15-046 shoe

Can you provide some instructions on how the 15-046 pivot shoe is to be properly connected to a 765 series plain channel balance? The channel balance I am replacing is exactly like your 765 series plain channel balance, but the pivot shoe on my window is a little different that the 15-046. It looks like the original pivot show was attached to the balance from the back side, so that there is no way for me to unhook the original pivot shoe from the balance without removing the entire channel balance and shoe together. Moreover, there is no cutout on the channel, so I will have to get the pivot shoe and balance out as a whole but cutting somewhere on the channel. For the lower sash, the cutout will have to be somewhere on the bottom half of the channel. I am quite confident that the 15-046 pivot shoe will work as a replacement, but it isn't obvious where the hook on the balance is supposed to connect to the pivot shoe. There are multiple slots on the pivot shoe

The pivot shoe in my window is not like the replacement pivot shoe. I have intentionally destroyed two pivot shoes while they were in the window trying to determine how the hook on the balance is connected. I have not been able to see a slot on the side of the shoe facing me to remove the hook. I suspect these windows were assembled in the factory with no simple provision to replace the pivot shoe or the balance. The balance also has to be force out of the channel because it is a little wider than the channel opening.