Put a field point in your insert, even if you can only get half a turn or so on the thing... metal will conduct the heat.
Avoid directly heating (espeically with a torch) your carbon arrow.... apply the heat to the field point itself. Grab onto the field point and she should eventually come out. Sometimes you will tear an arrow up beyond repair, but with some practice I've gotten pretty good at it. I like to cut at least 1/4" off the insert end after doing this as a precaution. You should NOT glue your nocks in carbon arrows or even aluminums with uni-bushings.
Remember this well though.... if there is ANY doubt about the integrity of the shaft... throw it out..... do NOT take that risk.