This page is a walkthrough for the Cayo Perico Heist Preparation Mission, Demolition Chargers. It’ll navigate you through the necessary steps to successfully acquiring the explosives
Go to the Grapeseed Train Depot / Go to the O’Neil Ranch
Once you’ve activated the mission via the planning board on the Submarine, then either use the sub to fast travel closer to the Train Depot or simply drive there yourself. After you’ve arrived at your destination, take cover and clear out all the O’Neil Brothers. Now wait a few seconds and you’ll get a waypoint to go to the O’Neil Ranch.
Here you’ll want to enter the building and clear out the enemies, then go over to the southwest corner of the home to find the basement. Continue taking down the O’Neils until one drops a Keycard, then unlock the basement door and collect the Demolition Charges. Finally, return to your Submarine to bring this mission to a close.