ST return efiling procedure

Please tell me the procedure for the efiling of the service tax return?

We got the login name and password from ST department .But after entering into the site - www.aces.gov.in  it asked for registration of ST1 and there is no link for ST3 return

Any one who efiled  the ST3 retiurn , Please mention the step by step details how to efile the st 3 return.

Thanks in advance.

Santosh