there should be a couple screws on each side of it's 'cage'. unscrew those, unplug the power cable and the ide cable from the back, and slide the drive out the front.
reverse the process to put the new one in.
good luck
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- + - ° GiRLie GeeK ° - + - °
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Therell be days/When Ill stray/I may appear to be/Constantly out of reach/I give in to sin/Because I like to practise what I preach