To change your password or the PIN code, you first click on "More" from your "Dashboard" menu:

Then click on Settings:

1. Password change: click on the pencil icon next to the password:

Type in your new password and then type it again to confirm it, submit that by clicking on Change password:

2. PIN code change: click on the pencil icon next to the Change PIN code:

Type in your new PIN code and then type it again to confirm it, submit that by clicking on Save:

Well DONE! Your PASSWORD/PIN has been successfully changed.