Step-By-Step Guide on how to change your MetaTrader master password using your Android: 

When you are on the MetaTrader application for Android:

1. Tap on the lines icon to expand the menu.

2. Tap on "Manage Accounts" to enter the "Accounts" page.

3.  On the "Accounts" page, tap on the account settings option and tap on "Change Password". 

4. Select "Change Master Password" and enter your current Live MetaTrader account password below. Enter your "new master password" and confirm it once more to proceed. Tap on "Next" to finish.

5. A confirmation screen will appear to accept this change. Tap "OK".