Send CAN message to open Car trunk

Hi all.

I am trying to carry out a project, and I am stuck in one of the parts, which is to open the trunk through a can message.
The pieces I have is an arduino uno and a bus can MCP2515.
I know that I have to do a sniffer to know what ID corresponds to the opening of the trunk, and that is my main problem, I don't know how to isolate that ID to be able to identify it. Can somebody help me? The car is a Nissan Leaf in case it helps.

Thank you very much to all!

First you monitor the CAN bus for some period of time to establish a baseline data set.
Then you continue to monitor the CAN bus while you operate the trunk button.

You compare the two datasets and look for IDs that only appear in the second dataset, or for data patterns that are different between the two datasets. Some may be actuator commands, others may be sensor values.

You do a series of 'replay attacks' using those messages until you find one that opens the trunk.

You should get the Bosh CAN Specification 2.0 and study it. Items do not use IDs they use addresses. The bus is CSMANDA so you must be careful as you can do a lot of damage sending the wrong message to the wrong "ID" Messages are prioritized by address and must be acknowledged. The Spec will answer a lot more questions then I can guess you will ask. This may void the warranty.

What steps will you be taking to ensure that this modification will not otherwise interfere with the safe running of the vehicle.

Are all the parts you are using, and the code, approved for use in vehicles ?