How to transfer ownership of documents

Infosys_Infosys_(infosysuser1_-_(deleted))

Hi!I am working on the problem of transferring ownership of all documents from a project member to coordinator, whenever the member leaves the project group. I am unable to find any suitable API for the same. I am working on JAVA platform to enable this functionality. Please guide me as to how to go about this problem of transferring of ownership. Its urgent.Regards,Mohit