repTheft Alarm- 2001 9-5

I''ve had situation over past few weeks of intermittent alarm siren.  Display says service theft alarm.  Based on reading the manual i figure it''s time to replace the siren unit (per manual it has its own battery, and the entire siren has to be replaced when its battery dies) I just called local dealer and it''s $500 to replace.  Anybody know if it''s possible to just disconnect it. If not...any suggestions on how to silence it?  It went off at home last night around 1AM and i couldn''t get it off...it eventually went off by itself after it woke half the neighborhood.   Previously it would turn off when i used the keyless entry.
 
Thanks. 

you have two options - fix the siren (I''ve got a spare set of batteries if you want, but you need to be able to solder) or disconnect the thing... both pretty easy but you will need to pry the siren unit open and than seal it with silicone...no big deal.