How do you remove and install a distributor in a 1965 Ford Mustang with a 289 V8 engine?

Remove the distributor cap. Remove the bolt in the clamp holding the distributor base to the motor, using a 1/2 inch box-end wrench. lift the distributor straight up. Note the orientation of the rotor. When reinstalling the distributor you'll need to stick it back in there with the rotor pointing in the same direction or the timing will be way off. The rotor will rotate slightly as the distributor goes back in. Also, the oil pump drive shaft is driven by a hex shaped hole in the bottom of the distributor. You have to wiggle it around a bit to get the distributor to slide down onto the oil pump drive shaft. Once you get it back in snug up the clamp bolt, put the cap back on the distributor, start the car and check the timing with a timing light. Adjust as needed by rotating the distributor. When the timing is right, and you do in fact have oil pressure, tighten up the clamp bolt.