I got my guitar a while ago and never ended up screwing the whammybar/tremelo (don't know which one it is) on to the actual guitar. I know where it goes (the onli empty hole that it can screw into into the part where all the strings enter the head, i think its called the bridge) but i'm not sure how to do it. I hav tried just screwing it in but i don't really know how it works and what it's supposed to do exactly. How tight does it have to be and how does it work?