Dependent on the distributor, first of all, the distributor cable must be removed, then the rotor, which is fixed by two screws, the advance weight springs and the weights as well. If at all it applies, remove the radio frequency shelter too. Remove the roll pin which holds the gear in position to the shaft and remove the gear and the spacers. Before sliding it from the housing, make sure that the shaft is not burred. Then, undo the cam weight base assembly and the screws that are fitted to hold the vacuum unit; the unit can then be lifted. Remove first the spring retainer and then the breaker plate assembly. Take out the contact points as well as the condenser, the felt washer and the plastic seal under the breaker plate. Wipe all the applicable areas with a cloth that has been rubbed in some solvent and examine the parts for wear, distortion and scoring; the rotor and 
Distributor Cap should in particular be replaced if cracked. Pack general purpose grease in the lubricating cavity in the housing; replace the old rubber seal with a new one and the felt washer as well. Mount the vacuum unit, the breaker plate and the spring retainer on the upper bushing of the housing. Add the engine oil on the cam weight base and place it on the mainshaft then follow the installation of the weights and springs of the engine. Place the mainshaft in the housing and fit the shims and drive gear and a new roll pin is required on this case. Last, fasten the contact point set, match the round and the square pilot holes and finally, the installation of the rotor before replacing the distributor.