here's the installation manual for the security system--you do have to take the driver's seat out but it's only 4 bolts--the entire alarm system install is definitely DYI--I did mine myself---took about 3 hours for everything--if you only need the control module (under the seat) it'll take about an hour to change

http://www.handaaccessories.com/S2000/s2ksecurity.pdf


The entire security system (including 2 new remotes) is $277 for 2001-2003 models from HandAaccessories.com----- that'd give you the new module and new remotes programmed to it (and a bunch of wiring you wouldn't need!
good luck with it!

 

thanks jetboater!!

 

picked up the part to do it myself and found out that it is the keyless control unit.... so not the unit that i thought, and not the one above-
the part number is 38380-s2a-a01

so it must be the one under the dash- will dig out the helms manual and see if that helps. looked under the dash and didnt see the unit, but guess it must be there!