What do I need to do?

Step 1.) Download the project from Github and compile it with Xcode.

Step 2.) Fix file ownership and permissions.

sudo chown -R root:wheel AppleIntelInfo.kext
sudo chmod -R 755 AppleIntelInfo.kext

Step 3.) Load AppleIntelInfo.kext?

sudo kextload AppleIntelInfo.kext

or with

sudo kextutil AppleIntelInfo.kext 

Warning: Do not copy the kext to: /System/Library/Extensions or /Library/Extensions and do not inject it with help of the boot loader!

Step 4.) Unload AppleIntelInfo.kext?

sudo kextunload AppleIntelInfo.kext

Where can I find the output?

The output of AppleIntelInfo.kext can be found with

sudo cat /tmp/AppleIntelInfo.dat

Note: This has changed in version 1.2 (data no longer added to /var/log/system.log)

There are five (5) settings that you can change in AppleIntelInfo.kext/Contents/Info.plist:

logCStates
logIGPU
logIPGStyle
logIntelRegs
logMSRs

All set to YES by default.

All possible bugs (so called 'issues') should be filed at:

https://github.com/Piker-Alpha/AppleIntelInfo/issues

Please do not use my blog for this. Thank you!