I mainly took on trying to do this because a friend said i couldn't but the internet said it is possible so i thought id try. I decided to do it from my mac to my core. I started by installing OpenSSH server on my core, then editing ssh_config and sshd_config to allow X11 forwarding. Then i logged into my core from my mac and i set the display variable to "1" since x was already running on "0". Finally i used the command xeyes to open that application and it gave me the error cant start display. I also tried startx but instead of starting a session on my mac it just started a new x session on the core.
So i was stumped and gave up, but maybe someone can see my error.