1989 300 SE Alarm problem

[smgovna]

Hello,

I'm in the process of purchasing a 1989 300 SE. When I went
to view/test drive the vehicle the owner installed a battery and
stated that the aftermarket sub/amps was causing a drain and
therefore had removed the battery. Well, once he had the battery
hooked up he unlocked the driver's door and activated the alarm.
It would not silence utilizing the driver's door nor the trunk lock.
Is there some way to disable the alarm without effecting the vehicle
in any other way?
The vehicle is truly a gem otherwise. It started right up, didn't run rough, and all the lights and functions worked properly.
This is completey above board and there is nothing clandestine going on.
I just need to know if I should proceed with the transaction or stay clear
of this deal.

Thank you for your time,

Steve