It's not difficult, but if you mess up, say good bye to your processor. Well, not exactly. It's just if you screw up, you might severely ruin it...and it will run even hotter, if done incorrectly.
well its worth it on a x2 3600+ brisbane.. cuz its only gonna cost another 56$ to replace it... but don't try that at home with your Core 2 Extreme Processor...
I'm a total beginner. I lapped my QX6850 and a Thermalright Ultra 90i. It lowered my idle temps about 8C-9C from a nonlapped QX6850 with TRUE 120. It's not that hard, but you should find a good guide online and TAKE YOUR TIME. It can take a couple of hours.