Advice required for Basics #77 Corey Graves arms

[britishbrickfan]

Hi all! I'd like some advice on how to remove the arms from Corey Graves' Basics #77 figure.

I'm trying to remove the jacket without splitting it or cutting it, and wanted to see if there's a method to remove the arms/shoulders from the torso?

I've tried warming the figure in warm water, but sadly that just softens the arm and makes it difficult to pull away from the pin into the torso.

Is there a technique I should be using for this, or do I need to cut the jacket away?