How to deploy sandbox edited code to production in zoho crm.

How to deploy sandbox edited code to production in zoho crm.

Hi, 
I have createdfunction in zoho sandbox and deployed to production. And after some day I get new requirements and edit my that function but I does not found the way to deploy edited function into production site in Zoho CRM.
When I check in the production function hasn't update.
Please let me know if any solution on that.