I have never done one... the trick would be not damaging it when removing from the existing barrel... quite possibly they are installed with a locking compound... so if at first it does not unthread with a fair amount of torque, heat would need to be applied. Not enough heat that would change the colour of polished steel... the heat treat would not be harmed if you did get it hot enough to a light straw colour, but less should be all you need. Above a light straw colour will most likely affect the original heat treatment.
So something solid is required to hold the barrel, an insert made be required in the bore so it does not collapse when the barrel is clamped hard... and some form of wrench made that will not damage the extension...