1998 1 button key fob remotes stopped working

Hi,

Both of the 1 button key fob remotes for my 98 Galant stopped working. Each of the remotes have a small red led that lights when the button is pressed. Replaced one of the batteries with a new one but no joy. Alarm can be manually armed or disarmed with the dash button and key so I think that the alarm system is okay. It appears that the alarm has lost it's association to the remotes, probably during a battery replacement a few weeks ago.

Is there a secret way to reprogram the remotes to work with the alarm?

Thanks,
Alan