I'm trying to upgrade the hard drive on an IBM Thinkpad i-series model 1451. I have a new hard drive and the details but I've run into problems trying to open the case. I've undone all the screws and the case still doesn't seem to want to come off. I'm afraid to pull too hard for fear of breaking something. Does anyone have any experience with replacing the hard drive in a Thinkpad and know if there is some special tool or trick to removing the case to access the hard drive? And am I going to run into problems upgrading a 2.1G to a 30G IBM drive?