Seperating a toggle?

[Ron Wood]

Luke,
A light penetrating oil like 3-in-1 can be used as a bath to soak the toggle, maybe for a couple of days. A bit of liquid wrench applied directly to the pin repeatedly may help but isn't good for a bath since it can discolor rust blue with prolonged exposure (of course if you are going to refinish the part, that doesn't matter). And sometimes the darned things just aren't coming out so it is off to the gunsmith to have them drilled out and replaced.
Usually the rear toggle joint pin isn't that difficult...that is why it has a retaining pin in the first place. Perhaps there was a burr kicked up the last time the retaining pin was installed or removed and that is what is holding the hinge pin in place.