To fit and take out the distributor cap, remove the negative battery cable than proceed. It might be required to take off the air cleaner housing and hoses in some models. Then, take out retaining screws of distributor cap and lift it at a right angle without incurring damage to the rotor blade. Unscrew and identify sparks plug wires at the cap and where provided, remove screws connecting rotor to distributor and while doing so, remember the position of the rotor in its housing to place it back. Check the cap and the rotor regarding damage and replace where necessary. To install it, reattach the rotor at the distributor shaft and apply the screw at the back (the retaining bolt, when it is there). Next, you will need to install the distributor cap and screw it in with the retention screws and then reconnect the spark plug wires in the appropriate positions. In case the air cleaner housing is taken out, its placed back, the vehicle started to make sure it was running properly and then the negative battery cable was attached in the end. Once the cap and rotor are removed, wash all the parts thoroughly using soap and water and where possible dry it using compressed air or even a soft cloth that is clean to touch, without leaving the lint or any moisture in them. After cleaning, check cracks, carbon tracks, burns, or other damage, make sure the carbon button on the cap remains and insure that the terminals are free of dirt or corrosion. Carefully inspect the rotor part and the spring to determine the extent of damage and change the parts exhibiting any form of wear or damages.