Anyone who's swapped an internal disk drive for a mcd! Help!

I'm following the guide at:
http://home.tiscali.nl/~smeyer/mpc/

and it looks like it shoulda been easy for me, but I can't disconnect the power cable from by old disk drive! I'm pretty sure it's the cable needed for my new card drive too. Finding a new opne seems pointless.
Can anyone help?

try to do it with a screwdriver

Already tried with a screw driver, but that doesn't seem to help much. Maybe brute force is the best option...

Lol, that's what I was thinking. I'm gonna wait a bit longer for answers before I just replace the wire.

Thanks for the help blinkinlights and lampdog. In the end I broke the power ocket on the zip drive apart to get the cable out. Shame the zip had to suffer, but the card drive and mpc work fine. I'm loving the speed and silence when loading and saving.