How To Loot From Bosses In Wow?

Q:how the heck do u the the drop loot stuff from bosses like ragnaros or prince thunderaan and stuff cuz i dont have wow but iwatch friends play n stuff and i ask them how do u get the loot they just confuse how do u do it?

A:1) right click on boss
2) loot everything
3) leave party
4) hearth
5) ??
6) profit