BMW: removal of a fatory fitted Alarm (E34)

Is it possible to remove a BMW factory fitted alarm from a 518i (E34, 1990)
and then fit this alarm into a 518i E34, 1994 ('facelift' model)? I know
that the alarm unit is under the rear seat and a multi-core cable runs to
the front passenger side's foot well. Where does this cable loom connect?
The alarm is a 'full closure' remote controlled system, and thus obviously
is connected to the central locking and electric windows / sunroof. The 1990
car does not have a electric sunroof, but the 1994 car does. Would this be
a straight forward job, or is it difficult? Is it a simple case of
unplugging the alarm from the 1990 car and plugging it into the 1994 car?
Once removed from the 1990 car, will the central locking and electric
windows still work on this car?


TIA,

Azhar