Rewrite old service requests to RESTful urls

I need to redirect incoming requests from urls like /GetUser.do?id=5 to /users/5.  I see that I can use the URL Rewrite Module to do this using Regular Expressions for GET requests.

Where I need some additional guidance is finding the best method to handle requests that are POST, PUT.  How can I get values from the Request Body and append them to the new url?

Example:

Original request: PUT /UpdateUser with Request Body {id: 5, name: Jane}

Redirected to: PUT /users/5 with Request Body {name: Jane}