[Bubbacpt]

As above, is it as straight forward as popping old battery out and putting a new one in or does the key fob need to be reprogrammed to accept it? Thanks

[adrek]

There's no need to reprogram anything, just replace battery and it will work.

[eye30]

I've replaced one and takes less than minute.

[The Gonz]

Don't overthink the operation of the fob. No power goes through the encryption/transmission circuit until you press your button, which is why it won't care about a battery change.