The biggest chore in restoring an old TV is usually replacing capacitors, which you can read about here.
http://antiqueradio.org/recap.htm
If you browse through the restoration section of my website, you'll find other articles that give you a general idea what's involved in making old TVs work. It is not just a matter of replacing a tube or two, as it was when the TV was only a few years old.
If you have never worked on any old tube device, you might want to consider getting a cheap plastic 1950s tube radio and practicing on that. That will build your confidence and, if you do make a beginner's mistake, you won't risk frying your TV. The radio also won't have such high voltages. Safety first.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html