Crank the engine over until you see the adjustment bolt on the clutch in the bell housing. Now while depressing the clutch pedal, push in the adjusting bolt and turn it clockwise to add free play and counter clockwise to remove free play.
For safety purposes you should use the access hole under the bottom of the bell housing to gain access to the flywheel. Then use a large flat head screwdriver to turn the flywheel to gain proper access to the adjustment bolt. Not all pressure plates have this adjusting bolt. Early models have a bolt and lock. Remove lock and turn ring to adjust clutch. Proper adjustment will be achieved when you have 3/8"-1/2" clearance between the clutch brake disc and the clutch release bearing. Once this dimension is achieved and not until, you can adjust your linkage for free play. If your clutch was properly adjusted when first installed achieving the correct distance between the clutch brake and the release bearing will be the only adjustment necessary, assuming no unusual wear in the linkage! These earlier clutches require a special tool for ease of the adjustment procedure, it can be done with patience and an assortment of pry bars, but the proper tool is the cats meow. By all means do not start the engine and depress the clutch prior to replacing the lock and lock bolt! This over sight will cause the adjusting ring to move to its full extreme and you will have to begin again.