Did you try this?
https://www.youtube.com/watch?v=R-3dClv64-A
2004 Infiniti FX35 Remote Programming
Note: You must have all remotes on hand when performing this procedure. Any remotes not used during this procedure will become inactive.
1. Close and lock all doors with the driver’s side power lock switch located on drivers door panel.
2. Insert key into ignition (DON’T TURN) and remove it from the ignition key cylinder at least 6 times within 10 seconds (this will need to be done at approximately one second intervals). You may need to insert and remove the key up to 10 or 12 times until your hazard lamps flash. PLEASE NOTE: Withdraw key completely from ignition cylinder each time. If this procedure is performed too fast or too slow the system will not enter programming mode.
3. Insert key into ignition and turn to the ACC position.
4. Within 5 seconds, push the LOCK button on the keyless remote. Your hazard lamps will flash. PLEASE NOTE: Do not press the button on the remote more than one time or the programming will not be successful.