My car is stalling when stopped at a light?

There are 2 tpyes of rotor. One has a screw to hold it in place. Look behind the rotor, opposite the metal end. Crank the engine until the rotor is facing away from the recess portion of the inner shield and check the recess area for a screw holding the rotor.

If no screw is found, you have to use 2 screwdrivers to pry it evenly from both sides to get it off. The inner shield can be used as leverage but you have to be careful to avoid cracking it. Sometimes it gets stuck real solid and the rotor would break leaving the inner part stuck to the distributor shaft.

Misfiring can be due to various causes and replacing parts without verifying if the part is faulty is going to be costly.

That should be a fault with the idling system. Cleaning the throttle body and IAC and readjusting the idling speed would normally cure the problem.

You did not specify what is wrong when stopped at a light. Is the idling speed too low or is it misfiring?

If idling speed is too low, you should be able to get the job done easily. Remove air intake hose and spray carb cleaner into the throttle body. Use a tooth brush to scrub the interior of the throttle body, paying attention to the area where the throttle plates closes. A rag would be useful to wipe off the grime. Spray carb cleaner until interior is clean. On top of throttle body there is the idle adjusr screw. Remove it and spry carb cleaner when you were spraying into the throttle body.

EACV (IAC)is located behind intake manifold.
Remove holding bolts and spray carb cleaner into the ports of the IAC and let it soak for a few minutes.
Use carb cleaner clean the IAC till it does not much signs of dirt inside.

Reinstall IAC and throttle adjust screw. Fully tighten the idle adjust screw till it stops, DO NOT force the scre when it reaches its end, back off 1/2 to 3/4 turn.

Start engine and let it warm up to operating temperature and check idling speed, adjust if necessary.