How do cow dung and vegetable waste change into manure?

They don't. Manure is just cow dung and vegetable waste mixed together. Nothing more, nothing less. There is no change.

Answer 2:They get broken down by microbes through the process of decomposition and fermentation. But really, both of these things are a form of manure. But they're not real manure, since you need to mix soil with these forms of waste in order for them to actually be a form of manure, and for the process of decomposition and break-down to be complete.