Access Instance of a Class from a differente Process in C#

Question

I have a project called "Core" that declares an Interface. And i have a project called "Service" that instantiates a class that implements that interface (it references the "Core" project on it's dependencies).

Both projects run independently, as i can run "Core" (it's an EXE). If i do, i'd like to verify if "Service" is running, and if so, get the instance of a class that is created on the "Service" process and call it's method.

It looks like this (almost).

On "Core" project :

namespace Core
{
    public interface IController { void Update(long ID, string Value, string Components); }

    public static class Utils
    {
        public static IController Controller;

        internal void Main(string[] args)
        {
            //Here, if "Service" is running, then get "Controller" from it
        }
    }
}

On the "Service" project :

namespace Service
{
    internal class ControlMe : Core.IController
    {
        public void Update(long ID, string Value, string Components)
        {
            //Do other things
        }

        internal void Main(string[] args)
        {
            Core.Utils.Controller = new ControlMe();
        }
    }
}

It should marshal somehow from one process to another, but i'm unfamiliar with Interop methods that would call that.