1. Login to G-Suite admin console.
Admin Dashboard URL: https://admin.google.com
2. After login to admin console click on Users button as shown on the figure below.
3. Now you can see email addresses lists and hover the mouse on the end of the email address, now click on button.
4. Now enter the desired password on the Password text box and click on Reset.
Or you can also use auto generated password from the G-Suite.