If the pimple has a yellow (fluid pus) dot in the middle, wipe it with alcohol and you can puncture the yellow part it with a sterile needle. Wipe off the pus (very gently) .
Do NOT squeeze this Pimple This will spread the infection and increase the risk for scars.
To calm the redness and reduce the size of the pimple there are 3 methods you can use.
 Put a 2-3 ice cubes in a clean thin towel or an old clean T-shirt. Put the rapped ice cubes on your inflamed red pimples for 10 seconds. Cooling the skin will constrict blood vessels and reduce the size and redness of your pimple.
 look for a Tooth Paste without Fluoride or whitening ingredients. You need to USE a paste/cream and NOT a Gel. Mix it with some baking soda powder to make it thicker. Apply it to your red pimples and leave it overnight The combination of tooth paste and baking soda powder, removes oil, dirt & dead skin cells.
 The lemon juice!! Lemon juice has citric acid and vitamin C. Lemon juice dries the pimple and is also a natural skin whitener. To reduce redness of your pimple overnight, dab a clean finger or a cotton ball in a halved lemon and apply the juice directly to the pimple.
A more “medical” way to reduce size and redness of since big Acne pimples overnight would be to use the easily available pimple care patch stickers. These are small stickers that disinfect and absorb fluids from big single pimples, reducing their size.
To learn more there is a nice video tutorial on how to get rid of a pimple overnight.