Lesbaru7

Hi all, I just upgraded from my '88 GL 278K, to a *new* '98 Forester S 152K. I bought it used, and am very happy with it. However, I went to install a keyless entry module, and found that it had a factory module installed! My questions revolve around this factory unit... I have read a couple posts telling users to get new FOB's on ebay... how do I know which one, and set it. Alternatively, would I be better off to cut out the factory H7110AS011, and just put in the aftermarket one that I have? Thanks! Tim