Insert the key into the trunk lock of your car, turn it off. Then lightly press down on the lock. If it is new will have to exert a little more effort. Please note that the key must be rotated parallel to the bumper of the car, and the Central lock needs to be opened.
Problems with the boot opening can also be associated with weather conditions. Warm up the car if it has long been in the cold and after 20-30 minutes, try to repeat the above steps. If this does not help, it is possible that the design frozen seal. Take the car for a wash, and wipe the grease seal, which you can buy in the auto shops of your city. Also after washing they handle and trunk lock.
If you have any problems with opening the trunk lock of the car "Opel Astra", check whether it is installed in it security. Try to enable and disable the alarm, re-open the Central lock, then re-insert the key into the trunk lock.
Check the battery of your car, it is possible that the trunk is not opened for this reason. If you are not able to charge the battery, use power from another vehicle. After this should work the Central locking with the FOB. Insert the key into the trunk lock and try to open it.
If you for any reason it is not possible to open the trunk of the car "Opel Astra" with a key, fold the rear seats in the cabin, then you will see the contents of your trunk. It's cover you can't open still, but this option is suitable for cases when you urgently need access to the contents of the Luggage compartment of the vehicle.
Do not go for self-repair of locks, use the warranty obligations of seller.