I'm not sure I follow. For remote start, you just need to splice into the ignition circuit.
If you mean pull the Ignition Switch Harness Plug off of the base of the Ignition Switch. Yes you can, no problem.
To be on the safe side, you would want to disconnect the battery while working on the electrical system until
such time when you are ready to test the system.
Keep in mind that even with the battery disconnected, air bags can be deployed via static charge from body
contact with bare Air Bag circuits / wires. Those wires are separate from the Ignition Switch Harness Plug and
are routed on the opposite side of the steering column (yellow connectors).