have changed batteries in key fob for 2000 isuzu trooper still not working

Ok, Open the driver door, insert the key and turn it to ACC then to LOCK three times in less than three seconds, close and open the door twice in less than 10 seconds. Repeat those steps. The door locks should lock and unlock after the second time of doing this correctly. Immediately after the locks cycle, press the lock button on the remote and listen for the locks to cycle again. Immediately after the locks cycle, press the unlock button on the remote and listen for the locks to cycle. Remove the key from ignition and test the remote.