computer woes, continued: defeated by screws

In the last installment my beloved laptop died, not recognizing its hard disk any longer, without the option to rescue anything from a Live CD, as its DVD drive had died a while ago.

Anyway, in an attempt to maybe salvage some of the lost data (my first HD failure since 1998, I've been complacent about frequent backups) I got myself an SATA/IDE to USB converter thingy, hoping to plug that into the disk, and then follow a data recovery guide, which explains how to image a damaged disk (I also got a shiny new external hard disk with plenty of space so I can store it) to then do repair work on that image and hopefully salvage stuff.

However, before I even got to that stage I've been defeated by screws. I got the disk out of the laptop okay, but it is in a metal frame you slide in, and the cable of the converter does not fit onto the disk while it is in the metal thing. But I can't get the screws loose. They don't budge at all, the only effect I'm having is denting my screw driver head. Admittedly said tool is a cheap and dingy little thing (I got it with some computer part or other), but I suspect if the screw driver was harder I'd only end up damaging the screws instead. :(