Trailor would be my first choise. But in the event you do not have one in the yard a good battery and good jumper cables to start with. From there a set of glow plugs may be needed, but you will need to see what you have there first. The fuel filters should be changed before turning the engine over, as well as a fresh oil filter and a fresh oil change.
Likely the 50 amp GP fuse is either out or blown. On that vintage it is usuaully mounted on the firewall, behind the engine and if not blown, it should be at least unscrewed and cleaned, if not replaced.
Take a volt- ohmeter and check for 12v at the glow plugs. Won't ever start without that.
Once the GP's are operable and the filters are changed out, locate the fuel hand pump on the injector pump and see if it will pump fuel into the IP. If it will not then that will probably need to be replaced, or possibly cleaned up and made to work again. Pump until fuel pours out of the top of the big fuel filter when loosened.
Then crack open an injector line and turn the engine over until fuel apprears there. Retighten and it may even start then, unless something else is bad. Did I mention that the fuel is likely to have green grass growing inside the tank? yes it will, best to drain the tank and dump in some algea kill, buy at a good parts store. Oh yes, refill with fresh fuel.