Re: Florida Craftsman Home
That member is usually called a "fly rafter" because it's set to fly away. They are hung in place by nailing down through the roof sheathing, so there are a lot of nails to cut or pull, etc., before it will be free. Measure before you pull it, and make tracings of the top cut and the notch where it sits on the knee braces, as those are exposed cuts and should be neat and precise.
How to reattach it is a good question. You probably can't attach the new rafter with the same nailing pattern (through the sheathing) without peeling back the roof. You could perhaps make a strip or blocks of wood as fastening points behind the rafter where they would not be seen unless looked for.
Remove not the ancient landmark, which your fathers have set.