FOR SCHALLER LOCKING TUNERS:
After removing the old string, loosen the thumbwheel screw in the back of the tuner of the string you are going to change. After inserting the string into the back of the tremolo plate in back and over the saddle (it is not necessary to remove the trem plate), run the string all the way up to the correct tuner. Re-tighten the thumbwheel screw until the string does not move out of the hole in the tuner (do not over-tighten) With a good pair of wire cutters, cut the excess string. Tune the string to pitch.
FOR FLOYD ROSE BRIDGES:
When replacing a string on a guitar with a Floyd Rose bridge, it is very important that the bridge should sit parallel to the body so as not to damage the finish. It is recommended to change strings one or two at a time; certainly leave at least one of the strings tuned to pitch while changing the rest, and place a soft towel or cloth under the back of the bridge to protect the finish.
Care must be taker not to over-tighten the saddle clamps. Push new strings through the saddle first with the ball end toward the nut so that you may fish the ball end under the string retainer to avoid damaging the finish. Strings should come off of the retainer toward the nut to assure that the string is touching the entire surface of the nut in order to keep the string from changing pitch when installing the nut clamp. You are now ready to tighten the strings at each end.