In order to change the Primary targets in Cayo Perico, you’d need to follow the following steps:
Firstly, start up the gathering intel, and make sure you only have intel unlock. 
Just kill these guys, and be careful not to damage the phone. 
Go to the communication tower, that is how you get to the target. 
A signal box will be in different spots the majority of the time. 
Look through the basement and all the cams. Here are the bearer bonds. So, get it if you don’t like it just die or get caught by guards.
The Fastest way to get back to the plane is to go back to Los Santos and Call Panvel to cancel the heist. 
After you cancel, just redo intel until you get the target you want. If you go back again, you will get the ruby necklace. 