This is really easy, honest. Navigate to RTBareBones/OSX. Double click RTBareBones.xcodeproj, it will open in Xcode.
Click compile and run, that's it.
For some projects (RTSimpleApp and RTLooneyLadders) if release is selected, a compressed .dmg is created of the final product. This is useful for giving to your users, easier than zip.
For examples other than RTBareBones, you still need to run the build resources .bat first on a windows computer. At least until someone ports RTPack.exe to OSX…