Here is how to remove the old shaft and install a new shaft
http://golf.about.com/cs/componentsc...llingshaft.htm
One thing that is not mentioned is that if the old shaft is graphite, DO NOT twist the head to remove -you must pull straight back. Otherwise, the tip will be severely damaged and you will not be able to salvage the the old shaft (unless you were planning to tip the shaft by an inch or so....)