HELP!! KEY Immobilizer Reprogramming
 

I just purchased a used 2004 Range Rover Freelander and the mechanics stated that the dealership said the car needs a key immobilizer reprogramming I have a key and it turns on everything but it won't start the car.....Please help!!!! Is there a way to get around taking it to the dealership? Also the mechanic didn't have a battery in the car I purchased a new battery once I purchased the car from him could that be the problem with the reprogramming issue?