I've followed the forum hints on this (interior light off, A/C off), and followed the handbook instructions - ignition switch to ACCESSORY, press and release demister button 3 times within 5 seconds, but nothing happens. Any ideas?

Note 1 - existing remote keypads continue to work correctly.
Note 2 - handbook shows demister button as curved windscreen shape, but on my EL futura the rear demist button has a rectangular shaped demist icon. I presume I'm hitting the right button.

Yeah, when you insert your key into the ignition chamber, only turn it to one then within 5 seconds of doing so, press the demister button 3 times then wait for the locks to cycle. they will then lock then to program them in just press one of the buttons on the remotes one at a time. each time you press one of the buttons on the remotes, if they just learnt the code, the locks will unlock then lock again. then do the same thing over again for the other remotes so go for remote 1: press button on remote then wait for doors to cycle. then repeat for other remotes

Success!! The handbook says 'press and release the demister button 3 times. I was pressing the demister button on and off 3 times - a total of 6 presses.
Tried it with only 3 presses and it worked first time. Thanks tony.martin11.

Glad to help you. when i first tried it i tried to do the same thing, but then learnt that you have to do it that way

Cheers