How to convert L2 to J1

[debphychem.ju]

Hi! I am from India and have been staying in USA from Apr 2012 with L2 visa (as a dependent of my spouse who is in L1B visa) and have an EAD. Our visa is going to expire on Nov 2013. Meanwhile I am working as a Postdoctoral fellow here and would like to get my visa status transferred to J1 after expiration of our visa.
What are the steps would I need to follow? When I need to file for the status change?
Please help me giving the details of the procedure.
Thanks