You could try a better lubricant such as Lubriplate or PB blaster. But yes, heat is the ultimate answer.

I think that there may be an old thread on the subject.
I have forgotten what was in it. I suppose you were reading the instructions, but if not, using a drift is exactly what is directed AND/BUT the pins go in one way only! I suppose I should learn about this as I will have to do it eventually also.

By the way, at least several years ago, MacKissic answered their phones and gave advise.

I remember the manual for my SC 183 says to address the situation with a punch to hopefully free the bolt as it is loctited, and heat if necessary. Hopefully the online help will come through for you.

Success - Heat did the trick!!

Thank you all for your help...

Pete