Iamnotageek.com has found an easier solution to unlocking those Level 1 bridges on your Thunderbird/Duron processors. Check out their review of the AMD CPU Unlocking Kit. here's a snip:
"A lot of you have probably unlocked Athlon's and Duron's the same way I have, using a mechanical pencil to join the L1 bridges. Many people doubted the author who first wrote the article about unlocking these chips with a pencil, but to many peoples surprise it turned out that it worked. While it did work many people found that over time it stopped working and the lines had to be redrawn."