Alright, i got this twelve string a while back and its been very good at staying in good shape.

Ok, well i was playing Assassin by Muse on it, and one of the strings popped.

I have no idea how these end pin things work, im afraid to mess with them because i have a tendency to screw everything up.

How do you mess with 'em? Do you pull em out? is it simpler or harder than that? I wanna get that last string back on cause an 11-string is definitely not as nice as a twelve string.
Assassin on a twelve string(I'm guessing acoustic) guitar?
No wonder the string popped.
I'm back. Cower in fear, mortals.

Claudio Sanchez is my hero.
Quote by obeythepenguin
Did you snap the string?

If the string's still attached to the headstock, detune it (not the entire guitar, just that string).

Then when the string's completely off, use a pair of pliers or something to remove the corresponding bridge pin.

And be gentler on your guitar! (Yes, this from someone who has to re-seat half the pins every time before putting his own 12-string away)

You didn't really just suggest that did you? I guess you did.
Not good, not good at all.
Pliers are ok for working on your lawnmower, but please keep them far away from an acoustic guitar. I can't honestly think of anything that could ever warrant having to use them on a guitar of any kind. Not when there are much better options, and for this, your brain and hands work nicely once you learn how.

To remove a bridge pin, as stated, remove all tension on the string(unless it's already broke), then grab the string about an inch or so from where it comes out of the bridge and push it back into the guitar, like you are trying to back it out the way it went in. It's a little hard to do with the thin treble strings, but it can be done. If it works, the ball end will pop loose inside of the guitar where it get's wedged between the side of the pin and the bottom of the bridge plate. Once you know you have the string loose, lift the pin out of the hole. If it's stuck, use the tool made for removing them. It's on the end of a string winder. There's a little slot that fits around pin, just below the head. If this fails then you can loosen the other strings and push the pin out from the inside. Note: NO PLIERS! Sorry, but it irks me to no end to hear someone using these on a guitar. It's just not right man! Ok ok ok, I'll give you one time where it's ok. To perform the process described below, then it's ok to use them to grip the string as you try to push it into the bridge. Since the string is going to be replaced anyhow, no harm no foul here.

And for the record obey, if you've got to reseat your pins after playing your 12er, then something's wrong with either the holes in the bridge, the pins themselves, or your last restring job. No way should they be coming loose on you from playing. They are a friction fit, and once inserted correctly and seated, they will stay that way until you remove them. They could be worn though and not be seating fully in the holes in the bridge, which could cause them to vibrate loose. Time for new pins if that's the case. If the holes in the bridge are worn, then a set of oversized pins can be had also.
Quote by obeythepenguin
You're right. I think I meant to type something else, but I was in class and a little bit distracted. Usually I use one of those winder/bridge pin remover things you can buy at the music store.

I never restring that guitar, so I'm sure that's not the problem.

I tend to smack the strings fairly roughly -- I have a naturally heavy touch with everything -- and for whatever reason they have been a bit loose before, so I usually check anyway, if only for paranoia. Contrary to popular belief, I am not completely incompetent with regard to setup issues, so I will be the judge of my own instrument, thank you very much.

Never said you were incompetent, just trying to lend a hand is all. A wise man once told me "No matter how much you know, there'll always be someone out there who knows more." Believe it or not, I get as much out of these threads as I contribute.