In SOC Encounter there are a series of commands to accomplish this, which partition the design along module boundaries. I'm pretty sure other tools do the same. The procedure is in the users guide.
Partition is not an easy job....If the person is having 5 yrs of experience also he can't say exactly I mean he should have atleast 8to 10 yrs of experience then only he can.............In this there will be so many constraints which we have to look...