From what I know they use locktite, I'm not exactly sure how it works, but my best guess was to use heat to break the bolt loose without snapping it, but I tryed that with my 98 expedition as a test and it snapped with little effort. Fortunately the entire rear end had to come out anyways so it wasn't a loss but I want to change out my gears in my 95 gt and I have little room for error.
What type of heat are you using? You will need to use a decent sized torch to really get it hot!! And you need to try and break loose the bolt right when the heat is removed. I like to use heat and some love taps with a hammer to try and break the threads free. It usually helps. But dont be afraid to use some very good heat on it. BUT make sure to try and clean off as much gear oil as you can before using a flame to prevent a bad flame up!
I agree with mucho heat....that factory Orange loc-tite is some rugged chit. I rounded the head off on the first one I did....From then on I used the torch and it's no contest...Dont be afraid to get it good and hot.
Small head size & Loc-tite is a recipe for trouble...
Its funny because all the work Ive done over the years and Ive never had one break. I go to do the gears in my car and it snapped like nobodys business. Luckily where it broke I was able to use a pick and unthread it. Most people arent that lucky.