How to reboot Keyless Entry / Security Alarm system

[remedy]

I have a 2002 4 Runner LTD with the keyless entry system / car security that was installed at the dealer. My window decal says KARR security system.

Our battery died a month ago, and now the activation LED under the dash is on 24/7. Not sure what this means, as I have no user manual for this.

Any idea if there's a way to reset this system without screwing up the keyless operation?

thanks!