Help with Multiple Motors/Intelligent Bricks and coding/ programming/ daisy chaining
Daisy chaining is straightforward. In your EV3 project, you click the little wrench in the topleft to open the project properties and enable the option "Daisy-chain mode" below the project picture. The EV3 bricks themselves need to be connected with the USB to mini-usb cables that are normally used to connect them to your computer.
After enabling the modes, the port selectors in your blocks will have layers, first layer being the EV3-brick immediately connected to your computer. 2nd layer the EV3-brick connected to that EV3 and so on up to 4 layers (4 bricks).

However, for the project you are describing, perhaps you could do with less motors and one brick would suffice: 


grabbing and lifting can be done with one motor as is is for example done in the gripp3r standard model included with the software. 
The double articulation of your claw arm might also not be necessary 
Perhaps the arm does not need to be able to rotate if the vehicle itself is maneuverable enough