Releasing mainspring tension on a pocket watch with a hidden click

[agregate]

I'm trying to release the tension in the mainspring on an Elgin grade 144 pocket watch and unlike my grade 291, this one has a hidden click and the main barrel is tucked underneath a plate.

I've looked online and found a single forum post stating I need to push a pin or very small object into a hole underneath the main barrel (which there is one) while simultaneously holding the stem in place to stop it from unwinding all at once.

The problem is, I've got a single screwdriver that fits in this pinhole and after poking around in a few directions, it doesn't seem to be releasing the click. I don't know if this is the right hole (it is the only one) that I'm putting it in, if it's supposed to be on a specific angle at insertion, a certain depth, etc. I've attached photos of the side of the movement and a diagram of what I am doing.

For what its worth, its a lever set.

[JohnR725]

With your bench in place you gently attempt to wind the watch which would take the load off the click then you can push in and then it will release you can let the bench key slowly spin in your fingers.

[agregate]

9 hours ago, JohnR725 said:

With your bench in place you gently attempt to wind the watch which would take the load off the click then you can push in and then it will release you can let the bench key slowly spin in your fingers.

I wasn't aware I had to apply load to get it to work. This method works a wonder. Thank you.