well, I don't know where the problem is, but that's maybe because I'm used to my S520. First unlock the strings at the nut, loosen them up, use the
allen wrench to loosen up the horizontal screws on the trem. Then remove the string out of the sadle. take your new string, cut of the colored ball. (make sure to cut it on that double winded part thing close to the ball for your low E, A and D strings. for the
higher strings, cut them clean.)
insert the string, tighten the screws, tune.
wash, rince and repeat for all the strings.
you might have to adjust the spring tension of your trem too depending on the string gauge.
at least that's how I always do it, if I'm telling bull****, someone pelase correct me
