1- cut it open with a disk grinder
2- lance it (good luck recovering cash or paper goods afterwards)
3- crack it using a stethoscope to find the right combination
4-if it uses a key pick the lock
5-if its a shitty cheap one you could use a magnet to fuck with the latches (very easy to mess up)
6-drop it off a very high building. it will crack open on impact (depending on how high it was dropped from)
7-if it uses an electronic pad you could hack it with either a code breaking tool or from dusting the pad for prints and figuring out the correct combo (takes forever)