GST NIL RETURN- REG

Dear frds/ experts,

One of our client started MSME small scale industry. Now he stopped that business within 8-9 months. He was paying & filing GST. Now he is filing nil RETURN from last 6-7 months, since he has stopped that business. Now he wants to close this GST number. But there is unclaimed ITC also....Now plz kindly advice me the step by step procedures to close & claim the GST.

Earliest reply would be greatly appreciated. Thanks in advance.

-Maya.