Let's see how it's used in a sentence:
Ex.: Você viu briga na escola hoje? Gabriel e Arthur caíram na porrada! Gabriel deu surra nele!
Did you see the fight at school today? Gabriel and Arthur came to blows! Gabriel beat the crap out of him!
Ex2.: Se não parar de me irritar, vou te **encher de porrada!
If you don't stop annoying me, I'll beat the crap out of you!
**I could also say "Vou quebrar a sua cara!".
Easy, isn't it?! Do you have any questions? Let me know in a comment below! :)