How to get rid of Lump on ear? Help!!?

I have a small lump behind my ear, it is very painful and I get them every few months, around my ear and in my ear, they go red and swollen then after a while, puss comes out of them, I had 1-2 once that actually went a browny-red colour (Like a lumpy bruise) They hurt a lot, and I want to know how to get rid of them? Thanks!!