Bleeding air is a 3-step process.
1. Turn off the fuel petcock at the filter. Loosen the filter bowl ring (nut). Open the petcock and leave it open until only fuel comes out of the top of the filter. Tighten the filter bowl ring and make sure there are no leaks. Make sure the petcock remains open.
2. The bleed screw for the injector pump is at the top of the pump, above where the lines go to the injectors. It's where the fuel feed line from the filter attaches to the injector pump. There is a screw/bolt on top of the banjo fitting that is the bleed screw. Open that screw until air-free fuel flows.
3. Open the hand throttle all the way up. Turn the engine over to make sure the injector pump is pumping fuel. If the tractor does not start, then you need to open each injector nut a little to bleed them while turning over the engine with the hand throttle wide open.
4. One more thing. . .make sure your fuel cutoff solenoid is open. Turn on your key switch and look to see that the PTO light is not illuminated on the dash. If it is, yoiu may also have a blown fuse #2. This is not a function of running out of fuel, but just a check if the tractor happens to not start after bleeding is attempted.
My guess is your tractor will start probably after step #2. I ran my TC45D out of fuel one time and only had to bleed the filter to get it going. The picture below clearly shows the bleed screw above the injector pump.