How to set field of JSON

How To
1

I have a variable json response (structure is changing) and I want to set one specific field to a given value. For example:

{
   "name": "Test1",
   "prop1": 24,
   ...
}

and I want to set the name to another value, ex. “Hello world”. Output should be:

{
   "name": "Hello world",
   "prop1": 24,
   ...
}

The only way I found is to use a hacky regex expression and replace the field in the raw json string which sounds little hacky.