First off, make sure the scab is completely dry and dab it if necessary. Once dry put moisturising lotion on it and wrap plastic around it over night. In the morning the scab should have disappeared. If it hasn’t, repeat the process.
With scabs on your face, here are a few more tips. Keep them clean; cleanse the area daily with some kind of anti bacterial soap. Check the affected area for infection (unlikely to occur from acne). Give the body lots of time to heal, it could take a long time for a scab to completely go away but keep checking for signs of healing. When a scab looks healed it is often safe to scratch or rub it off.
Make sure you do not pick a scab before it is ready to go and don’t use makeup to hide any scabs on your face left by acne. This stops them healing. Try not to wipe your face after washing it, instead pat it dry with a towel (doing this stops the skin from splitting).
If you are having recurrent problems with spots it might be a good idea to speak to a dermatologist as they can give you expert advice and provide medication or chemical peels if necessary.