There is no manual release switch for these, so this isn't going to be a simple fix. One way is to remove the interior switch and jumper across the pins inside the connector to get the electronic release to engage, and this will only work if the release solenoid is functional. Another would be to have a locksmith maintenance or rekey the lock. Most likely you will have to replace the the switch, release solenoid, or the lock.

http://www.automotix.net/autorepair/repairtips