1) The new MT4 server name associated with your account will be found on your home page, after you login, in the MT4 section below the Download button (e.g. OANDA-XYZ)
2) To add the new server, open your MT4 Client and go to File > Open an Account
3) In the new window, click on "add new broker like 'brokerName' or address mt:company.com:443"
4) Enter the server name from step1 (e.g. OANDA-XYZ) and click on Scan.
5) Once successfully added, the server name and OANDA will be appear under your list of Trading Servers. Select the server and click Next
6) In the following page, use your MT4 login credentials and click Finish to complete the login process. Please ensure that the Server identified matches the server identified in step 1