Was the separation of boiler and frame particularly difficult?
Very much so, it was decided that, in this case, replacing the smoke box would be less of a hassle than separating it from the saddle. That meant that the smokebox had to cut without damaging the saddle or sending any debris down the main steam lines to the cylinders.
There were also more than a few extra brackets that had to have their bolts either removed or burned off so that we could get the boiler out. A few (small) holes also had to be cut in the floor.
That's about all I could tell you, when Hans gets back in this thread he can probably say more about what was needed.
