As previously mentioned, a blowtorch works well in this situation.
When you heat it up real nice, hit it with some oil... right in the open crack where the pipes connect.
If you can manage to do it right (I have only been able to do it once in one try) then it will shock the inner pipe first, then you yank on it.
Again I have only done this once, and I can only guess what happened to cause it to come out so easily.
Must have been my lucky day.
[COLOR="Red"]Any Jeepers in Edmonton, AB
I am on channel 33.[/COLOR]
I live, I ride, I am JEEP.