However, even that is not enough as it still does not help you pin-point the exact locations of some of the access points outside of casino. You can buy a casino model for your prep board for GTA $130,000 which shows them the locations of all the access points.
One of the prep mission includes finding the access points and points of interest (POIs) during casino and vault scope out missions. Among the mandatory prep missions come optional prep missions as well, which you can carry out to make your heist easier.
In order to carry out the heist finale, you must go through several heist preps. This part of the guide will show you how to find the different access points and POIs to unlock all three casino heist approaches - The Big Con, Aggressive & Silent and Sneaky.
