How to shift office from one city to another in gst?

Hi All,

If i want to change my office location from Mumbai to Pune (in Same State) then what will be the process? My Service tax registration was in Mumbai and i migrated into GST but now i want to shoft my office to Pune. How can i do it? What documents will be required? How many days may it take? When will i be able to download updated GST certificate?

I am looking forward for your kind reply.

Thanks in advance for your help.