Source: http://lifehacker.com/5572387/our-hackintosh-build-upgrades-without-issue-to-1064
Apple released Mac OS X 10.6.4 just over a week ago, and if you've been waiting to hear whether it works on systems built following our start-to-finish Hackintosh guide or the newer no-hacking-required guide, I've got good news: I finally got around to installing the update, and the Hackintosh upgraded without issue.
That means the process involved in updating your Lifehacker-approved system is dead simple—it's the same one regular Mac owners use. Launch Software Update, grab the update, and restart.
Note: To be very clear, I'm referring only to Hackintosh systems built using our instructions. If you built a different Hackintosh, be it a netbook or any system that didn't use the main recommended hardware in our build, your mileage may vary. I can only vouch for the system I built.