The first thing is to take shower with warm water so that your pores are opened. While taking shower with warm water use body loofah on the area where the in growth hair problem occurs.
Now use a good quality scrub and scrub your skin gently do not hurt yourself while scrubbing.
After scrubbing you will have to pluck out the hair, before doing that make sure your tweezers are clear from germs. If you are not sure then soak your tweezers in the liquid of rubbing alcohol and then clean it with a cotton pad.
Carefully analyze your skin and see if the hair is still in the skin or not usually due to scrubbing hairs do come out, if they are out then with the tips of the tweezers get hold of the hair and pluck them out.
If the hair is still in the skin and you are not able to bare the pain then let it be the way it is and wait until it heals itself. But if you wish to get rid of it then apply a moderate amount of antibiotic ointment and break the skin with a clean needle and take the hair out from the curve of the hair by slightly pulling it upwards. Then by using your tweezers pluck them out.