lexus key programed

does any one know how to program a 98 lexus gs 400 second key I have 2 master keys and one 3rd valet key not programed

To delete all but one key from the unit: Type E 1. Simultaneously depress and release brake and accelerator pedals 1 time. 2. Insert existing master key into ignition. Do not turn the key from the OFF (LOCK) position. 3. Within 15 seconds of inserting the key, depress and release the accelerator pedal six times. 4. Within 10 seconds of completing the above step, depress and release the accelerator pedal seven times. 5. The security light will flash, indication all keys other than the one being used have been deleted. 6. Remove the key from the ignition cylinder within ten seconds. It will be the only key still programmed to work     Add Duplicate Key: 1. Simultaneously depress and release brake and accelerator pedals 1 time. 2. Insert existing master key into ignition. Do not turn the key from the OFF (LOCK) position. 3. Within 15 seconds of inserting the key, depress and release the accelerator pedal five times. 4. Within 20 seconds of completing the above step, depress and release the brake pedal six times and remove the key. 5. Within 10 seconds, insert the new key into the ignition. 6. Within 10 seconds, depress and release the accelerator pedal one time. 7. After 80 seconds the new key is registered and the security light will go off. 8. Remove new key and depress and release the brake pedal 1 time.