Excise exepmption if cenvat credit not availed

Dear All

                   Currently we are availing cenvat credit. Now the company has decided to stop availing cenvat & avail exemption of 1.50 crore from next year. Our current turnover is greater than 4 crores. What is the procedure for the same? Can any body guide me?

I want to say if we do not avail cenvat credit, what is the rule of charge Excise Duty? After Sales Cross Rs.1.50 Crore or else?