Before replacing the transformer, just for giggles, remove the paper wrapping CAREFULLY to expose where the fine transformer wire connects to the lead wires. Remove the paper in such a way that you do not tear the transformer wires. Often enough the transformer wire has burned or broken right by the lead wire. Simply reconnect the wire. If you must remove a turn, if you feel that you can, remove the iron core and then remove a turn to undo enough wire for fastening to the lead-in wire. Resecure everything and melt a bit of parafin into the paper layers to hold them in place (found at the super market and some craft stores....if you can't find it, use a candle....vanilla scented transformers are fine!). Then, using either friction or rubber electrical tape (friction is the best), wrap a layer or two around the paper to hold everything in place. Reassemble the iron core around it.
Not every transformer burns out this way, but enough do that people recommend this. My RCA Color Television crosshatch-dot-color bar generator was repaired by me when I found that one of the transformers had burned out as described above.
Thomas