My brother (being the genius that he is) lost one of his keyless entry remotes and broke the buttons out of the other, and now for Christmas he wants a replacement. Is this possible without replacing the whole alarm system? Tomorrow I'm going to call the place that installed his alarm and see if they can help me out, but any idea of what I'm going to hear will be much appreciated.

yeah you can get replacement remotes easily... check ebay for the cheapest prices

What he said, I just did it to my car, but shoulda waited like till 25th cause my bro was gunna spend the $90 bucks.. damint

Yes you can get replacements. I got a replacement from the store where I bought my security system for free because I have spent so much money in their store, it was supposed to be $90. >>

Thanks, but I was just looking around on ebay and it seems the only replacements are for stock systems, and he has aftermarket...

There are replacements for all types of different alarm systems. It varies from company to company. Get the model of the alarm system or the serial number and search that way.