How to break into a safe?

My roommate took my pot and put it in his safe, and I want it back. It was about 600$ of weed and he is out of town for i think 12 days. It is a Sentry Safe and it says CS-2 above a numberpad. Is there a way I can get in without damaging it? I am not stealing anything from him or anybody else, I just want my stuff back, I payed good money for that and I shouldn't lose it because he isn't into the herb.