Presumably everything that has got hot [for some defined value of hot] or [given that the fire wasn't instrumented] can't be proven not to have gotten hot will need to be replaced, simply because its structural properties are no longer a known quantity and it might fail under loads that it previously wouldn't have failed under? So the visibly damaged area will need replacing, but so will all the surrounding areas that were exposed to the fire directly, and the radiated heat of the fire indirectly... given the obvious known properties of hot gases, that could mean a hell of a lot of the top half of the fuselage needing to be replaced, and then there's the rear bulkhead, and the tail fin...
So, how do you patch a plane that has such major and unquantifiable structural damage up to a point where any certifying authority will let you ferry it somewhere for repair, given that for all anybody knows, the tail fin if not the entire back end of the plane could shear off the first time they use the rudder during climb-out from Heathrow and they could end up... improving... Slough High Street?