I don't recommend this,but I've always drained those things myself using an 18 g pin.Takes some time to get all the pink puss out,and usually I've had to preform the proceedure the next day to get the last bit out.It seems to build up a little again after the first extraction.So I've found it necessary to go back and draw up a few more cc of the pink puss.You don't need to go deep at all when inserting the pin.The puss build up is right under the layer of skin.
Like I said.I don't recommend doing this.I'm crazy so take heed in what I said above

A medical professional should be your first choice.