really - how?
page 97 owners manual:
Replacing lost transmitters
If a remote transmitter has been lost and you would like to remove it from the vehicle’s memory or you would like to purchase additional transmitters for your vehicle (up to four may be programmed into memory), take all your vehicle’s transmitters to your dealer for programming. It will be necessary for your dealer to reprogram all the remote transmitters to your vehicle while performing this service.
in the programming instruction that cam with the remote keypad:
Lincoln LS 2000-2002 - Dealer diagnostic method of programming trammitters and keypad only.
I believe you are talking about adding additional keys to your cars PAT system (which we are not talking about here) - which is done:
Programming spare keys
A maximum of eight keys can be coded to your vehicle. Only SecuriLocky keys can be used. To program a coded key yourself, you will need two previously programmed coded keys (keys that already operate your vehicle’s engine) and the new unprogrammed key(s) readily accessible for timely implementation of each step in the procedure.
If two previously programmed coded keys are not available (one or both of your original keys were lost or stolen), you must bring your vehicle to your dealership to have the spare coded key(s) programmed.
Please read and understand the entire procedure before you begin.
1. Insert the first previously programmed coded key into the ignition and turn the ignition from 1 (LOCK) to 4 (RUN) (maintain ignition in 4 (RUN) for at least one second).
2. Turn ignition to 1 (LOCK) and remove the first coded key from the ignition.
3. Within ten seconds of turning the ignition to 1 (LOCK), insert the second previously programmed coded key into the ignition and turn the ignition from 1 (LOCK) to 4 (RUN) (maintain ignition in 4 (RUN) for at least one second but no more than ten seconds).
4. Turn the ignition to 1 (LOCK) and remove the second coded key from the ignition.
5. Within 20 seconds of turning the ignition to 1 (LOCK), insert the new unprogrammed key (new key/valet key) into the ignition and turn the ignition from 1 (LOCK) to 4 (RUN) (maintain ignition in 4 (RUN) for at least one second). This step will program your new key to a coded key.
6. To program additional new unprogrammed key(s), repeat this procedure from step 1.
If successful, the new coded key(s) will start the vehicle’s engine and the theft indicator will illuminate for three seconds and then go out.
If not successful, the new coded key(s) will not start the vehicle’s engine and the theft indicator will flash on and off. If failure repeats, bring your vehicle to your dealership to have the new spare key(s) programmed.