Not enough information.
On my 1997 Discovery trying to unlock any door other than the driver's door sets off the security alarm, so I would not count on unlocking all doors from the rear door.
The only thing I can say I have spoken to Land Rover and they tell me the only thing in common between a Discovery 1 and a Discovery 2 is the rear door, no other panels are swapable.
To shut of the SLS audio alarm on a Land Rover Discovery by inserting the key into the door. You can also turn the ignition on partially and leave it in that position for 10 minutes before starting the vehicle.
Inside panel passenger side under dash by door.
This is a complicated procedure. It is best left to the professionals so take the vehicle in to your local mechanic.
it is under the hood right in the corner nearest the drivers door and it takes DOT 4 Brake fluid
See the following site http://www.rd.com/19539/article19539.html
This happened to our 1997 Discovery once, and it was the assembly inside the door that had gone bad. If you are a DIY kind of person, you can take the door apart and order the assembly and redo it yourself. A manual on your specific Land Rover will help to complete the project.
It may be that your Heater core is leakng Antifreeze. Not good.
tire jack located in engine compartment beside the battery, rest of tools in rear door pocket.
Make sure your windows are right up and the back door totally closed as the air sensors in the cabin causes the horn to blow.
I don't know offhand, but the proper tire inflation measurement is printed on all vehicles in the owner's manual and inside the door jamb. If the car is physically with you, you can check there.