Have tank at least half full.
Turn valve off at tank.
Change filter and large o-rings, the larger goes in the groove in the filter head, the smaller goes in the bowl.
Open bleeder on the filter head, turn fuel on.
When bubble free fuel come out of bleeder, close it.
Using a 5/16 wrench remove the bleed screw from the injection pump body.
With shutoff cable pulled out (off) crank engine. You will get clear fuel, then air, then fuel again.
When you get a clear stream of fuel splashing on the right front tire, install the bleed screw and start the tractor.