changing a user's email using api

Hello,

changing a user's email: 

Step 1: Add the new email as an email alias for the user's account with the Create Email Alias endpoint. Step 2: Set the email alias from step 1 as the primary email for the user's account using the Change User's Login endpoint. Step 3: Delete the old email using the Delete Email Alias endpoint.

step1 add the new email using Create Email Alias endpoint the result also sucess

i am getting error in step2 change email set to primary using Change User's Login endpoint

Below are the parameters pass to api

login  :***email address removed for privacy***
userid :3*********

o/p:
{"type":"error","status":405,"code":"method_not_allowed","help_url":"http://developers.box.com/docs/#errors","message":"Method Not Allowed","request_id":"y7tdvofqyhowzxj4"}

let me know where i do the mistake and help me how to solve above senario