How do you play Xbox 360 games on your PC

No, it's impossible. Xbox 360 games are made for the Xbox 360, not PC. They both have very different hardware infrastructure, so software made for 360 would not be compatible.
It may be possible in the future, as PCs become faster though. You may have heard of emulators that run NES games - they get away with this because modern PCs are fast enough to emulate the hardware of those old systems. Xbox 360 is not old, immensly faster than NES, and millions of times more complex. If it were possible to emulate Xbox 360 it would most likely take years of work and research and only run on the top supercomputers of today.