First, remove the rubber bumper at the bottom of the door. This is the lower side glass stop. With that rubber removed, you should be able to lower the glass all the way down to the bottom of the door. Now you can get to all of the screws that hold the outer window fuzzies in place. The glass will come out much easier with the outer fuzzy off the car. Then it's just a matter of removing the fasteners that connect the glass to the crank mechanism/sliders. The factory changed the glass hardware through out the years so I'm not sure exactly what was used in 74. My 73 used these weird stamped steel nuts and fiber washers to hold the glass to the plastic sliders.
You don't need to unbolt the rear slide support from the glass. You can remove the rear track along with the glass or keep it attached inside the door. I would personally leave all the tracks in place.(less pieces to store and possibly lose) You can remove them, refinish them and reinstall them right before you're ready to put the glass back in.
