I am not a guru on this field, but with some handon to this kind of work.
Well you have to use a meter to make sure what polarity does the trunk release work with and the output of an alarm.
In your case, the trunk release work with (-) and the alarm is (+), you have to use a RELAY to convert the polarity.
Use standard auto relay for the purpose. Wire the alarm output (+) to 86 and Ground to 85. Another ground to 30 and the output 87 to the trunk release wire.