Petra Regent said: >I have recently purchased a 40 Gb hard drive to replace the 10 Gb hard drive >in my G4 Titanium Powerbook . I have been told that it should be possible >to do this replacement myself, but I can't find any information anywhere >about how to do it. Can you help me ? First of all make sure your grounded. It's a good idea to use ground wrist strap. While you can get away without one, there's still a risk to cause damage to the boards. If you don't use one make sure you sit down, touch the framework inside the book and make the swap in one session without moving around. Use the guides as have been suggested. Be firm yet gentle when working with parts. If you must use force something isn't sitting right. Check carefully what's going on. You must use the Torx 8 driver in most places, unless your bottom plate is fitted with cross-screws. I've seen a 550 with those. Be very careful when loosening from and refitting the drive cable to the motherboard as well as to the new drive itself and also with the screws to the side of the drive. All four screws needs the rubber cushions. Don't lose these! It's possible to put these side screws in at the wrong angle, messing up the groves if one is not careful, so look out for that. Also, the plastic shielding the drive from the trackpad, should be turned the right way. Just pay attention and you'll see. When putting back the bottom plate make sure it slides into the retaining clip near the DVD-drive slot. That should cover it, I think. Just take it easy, be calm and think on what you do and you'll be fine.