What is the best way...?

Try being honest with the people that matter. Just come right out and say "I'm going to be unavailable for a time due to some intensive studying." Make sure you let them know that you will be turning off the phone and eliminating contact for a while, I recommend this so that you are not reported as a missing person. If you can afford it, rent an apartment for a month or so (you didn't give a time) or a cheap motel room. I don't think you can do the no emotion thing, that's easier said than done. Good Luck and I hope you enjoy your own company!