How do I open the computer base to access the inside components?

The power socket on my HP Pavilion 9500 has a short in it (most likely a cracked solder joint) where the AC power adapter is plugged into the computer. I have removed all of the screws from the bottom of the laptop, but the bottom does not seem to want to come off. I hate to apply too much pressure to anything, as really don't want to break anything else on the computer. Nonetheless, I think if I can get the bottom off I could solder the cracked AC power socket. Any suggestions?