How hard is this to do/is it possible at all? I have dreams of running a natural gas line out to my garage and then laughing at my propane tanks as they collect dust....
I am in the heating and air conditioning business and we do these types of conversions on furnaces all the time. You would need to contact the manufacturer of your burner and ask if a conversion kit is available. Most times there is a different orifice for the burner and/or a different regulator. Propane works at a pressure nearly double that of natural gas.