what is the URL I should use to edit a user account?
To update a user with Drupal Services, you make a PUT call to:

?q=[my-endpoint]/user/1.json


Replacing [my-endpoint] with the machine name of your Service endpoint. Here's some example JSON to PUT:

{
  "uid":"1",
  "name":"bob",
  "mail":"bob@hotmail.com",
  "current_pass":"secret",
  "pass_pass1":"new-secret",
  "pass_pass2":"new-secret"
}


You must also attach a header to your call with a name of X-CSRF-Token using a value that can be retrieved here: ?q=services/session/token