The Lexus car remote key control model ES300

Try this:

1. Start with key out of ignition, drivers door is open all others closed and
drivers door is unlocked.
2. Insert key into the ignition (DO NOT Turn) and Pull key out.
3. Perform these steps within 40 seconds.
A. Using the power lock switch on the drivers door, perform 5 lock/unlock cycles
starting with lock. Use an even pace and try to go about one cycle per second.
(1Cycle = 1 lock and 1 unlock).
B. Close, then open drivers door.
4. Perform these steps within 40 seconds.
A. Using the power lock switch on the drivers door, perform 5 lock/unlock cycles
starting with lock. Use an even pace and try to go about one cycle per second.
(1Cycle = 1 lock and 1 unlock).
B. Insert the key in the ignition cylinder.
C. Turn the ignition to ON (Do NOT Start) then back to OFF.
D. Remove the key from the ignition.
5. Press any button on remote for a minimum of 1 second.
System should now lock and unlock doors once.

6. Close and open drivers door.
7. Press any button on remote for a minimum of 1 second. System should now lock and
unlock doors. Once to confirm programming, twice to indicate programming failed.
8. Repeat steps 5, 6 and 7 for additional remotes.

The 1997 ES 300 Lexus car remote key control doesn't work with replaced by new battery. pls help, thanks in advance to somebody who will answer my question.

I have a 1997 es 300 replaced the battery the board inside still looks good. made sure all the fuses that anything to do with wireless and or theft deterent system were good. y is it so difficult to get it working again?