That's... tricky. The user guide puts it rather bluntly: 'It is important that you write your password down and keep it in a safe place, because if you cannot remember your password your only option will be to return the device to our support centre so the password can be reset. In this process all your trip data will be lost and you will incur shipping charges – so please don’t forget your password!'
However, since you've got the password remembered by your other machine, you may try using one of the so-called password revealers. One of those programs may be able to show the password hidden behind the asterisks.