I know how to get rid of it, or atleast make it a lot less noticeable if you attend to it almost immediately, but a day or so later after the bruising has set in....
better put on some make-up or a collared shirt and tie.
but you can try this technique anyway if you want, but it might be too late for you:
step 1:
get an ice cube or a frozen spoon and place it on the hickey till the area is numb.
step 2:
take a lipstick cap or any cylindrical cap with a smooth edge and press it down on and around the area and twist and pull. this might make a popping sound if you get good suction.
do this repeatedly until it doesn't look like a hickey anymore.
repeat step 1 when the numbness wears off (step 2 kinda hurts
)
this will break up the blood vessels at the surface and stop it from pooling all in one place and causing a very noticeable bruise.