Try disconnecting the battery, leave for a five to ten mins then reconnect it. This usually unlocks all doors.
If it doesn't, disconnect the battery again and try the following.:
You will need to remove the screws that hold on the door card, then try and prise off the card. It will probably bust all the clips and you may need the break the door card to get it off but it's easy to pick up a replacement one.
Once off, see if you can swap out the solenoid for another one and see if it unlocks the door.