Its best to take to a place that installs alarms but usually they will install the module unit near the steering coloum on the firewall. I am assuming that your remote does not say Honda on it. Did you only get one remote with it?
Even though you changed the batteries only a few months ago and the remote still lights up,it still may not have enough voltage to arm/disarm the unit. I would first try out some fresh batteries before messing around with removing the unit.The remote has new batteries in it - that I replaced a few months ago and it lights up.