Thanks for writing you query.
I would like to suggest you that donot try to drain the boil by yourself. If not properly done and if it gets infected, it can result in dangerous results due to spread of infection to the brain.
You should seek medical help
for incision and drainage
of the boil under aseptic conditions.
Antibiotic can be nedded to prevent any infection.
Culture/Senstivity of the fluid/pus drained can be done to know the appropiate antibiotic.
I hope this is helpful to you.