strut mount in rear diff? Bolt or stud?

I need to remove the shock mount in my rear diff. Bike is an 82 KZ1100 shaft drive. Is this thing pressed in or screwed in. I tried turning it but after putting a lot of force on it I was scared of cracking the aluminum housing.

Here is a pic of what I'm referring to.

It's suppose to be a stud according to the OEM parts diagram.

Some heat may help as its a steel stud in aluminum. The aluminum wil lexpand a little quicker than the stud stud will.

Later, Doug

Thanks doug, i will try that,
Mike