return in excise

Hi,

scenario is: i have sold 10 nos excisable finished product from excisable plant to our customer.(OR-LF-F2-J1IIN) Relevent registar RG1 updated ,extraction done. After two months , customer returns 2nos back to plant.Return OR-Return LF- after that what do i have to do to reverse cenvat entries from excise point of view.

a. J1IH or J1IS ?

b. If its J1IS what is ref document type to be used?in which register will it get updated ?

c. If its J1IH which option we need to take ( other adjustment,additional excise ..etc..) and which registers to choose ( RG23A,RG23C, PLA,Fortnightly payment ) as Finished goods is getting returned

kindly advise pls...

thanks

-UK