Well, I just bought and installed a Taisol h/s yesterday (the latest HUGE one that has been getting rave reviews). Of course I had to take it back off and put it on again because I did the pencil trick wrong. I took the power supply out of my case so I could have more room and get to the clip from the side.
I pushed down with my hand on the clip while CAREFULLY used the screwdriver to pull it outward. After 3 attempts, it came off. Luckily for me, it wasn't that difficult. It felt to me like it should have been on the chip a lot harder, but I guess it must be alright. I have overclocked my Tbird 700 to 912 and running RC5 at 43C with no case fan.
Best of luck, and be careful.