Java 9 VarHandle Implementation Details

I have been reading about VarHandle in Java, from the documentation the access modes are grouped into the following categories:

read access modes, such as reading a variable with volatile memory ordering effects;

write access modes, such as updating a variable with release memory ordering effects;

atomic update access modes, such as a compare-and-set on a variable with volatile memory order effects for both read and writing;

numeric atomic update access modes, such as get-and-add with plain memory order effects for writing and acquire memory order effects for reading.

bitwise atomic update access modes, such as get-and-bitwise-and with release memory order effects for writing and plain memory order effects for reading.

JEP 193: Variable Handles

Found following code sample from Using JDK 9 Memory Order Modes

import java.lang.invoke.MethodHandles;
import java.lang.invoke.VarHandle;
class Point {
   volatile int x, y;
   private static final VarHandle X;
   static {
     try {
       X = MethodHandles.lookup().
           findVarHandle(Point.class, "x",
                         int.class);
     } catch (ReflectiveOperationException e) {
       throw new Error(e);
     }
   }
   // ...
}

What I am trying to figure out is how does it achieve this, what is the underlying implementation and how to use all these access modes ?