Registration of importer

How can an importer of excisable goods pass on the credit of CVD paid on such goods to the buyer.

1) Do he need to take registration under central excise as an importer or as a FSD/SSD?

2) Do he needs to issue a supplementary invoice to pass on the credit?

3) How can he pass pass on the credit of CVD in case of endorement of bill of entry?

Please reply.................