I just removed my Merlin 2 gimbal to see if there is a way.
From what I see, the small tongue that locks into the groove in screw-housing on the stage will completely retract if you apply sufficient pressure to the small button in the guide. That's the button you have to press to allow the guide to screw in or out.
Provided you can get the button down below the surface of the guide, that should retract the tongue enough to allow the thread to start unscrewing.
As far as I can see, the Merlin 2 gimbal cannot be disassembled - once the factory build it, it's fixed for the life of the unit. The tiny pins for each bearing appear to be press-fitted and the ends swaged slightly into place.