1930 Model A - stuck temp gauge bolt

[KCW]

Hi everyone -

I’m trying to replace my Model A temperature gauge. The bolt where it enter is stuck. Attached is a photo. I can’t get it to budge at all. I’m an amateur and was wondering if there are any tricks to remove it. I do have a portable torch I could use to heat it but thought that could be dangerous. Can I use the torch? If not, how to I remove the bolt?

Thank you!