tramp: put X forwarding and custom port to ssh

[Biocyberman <biocyberman@gmail.com>]

Hello Emacs users

I am a new emacs user,and I thought the problem I have is solved long time
ago. However, after many google searched, I could not find a working
solution.

The goal:
I have a working X forwarding setup when working with SSH outside emacs.
Since TRAMP is so attractive, I want to make X forwarding work inside emacs
as well. This will help  me to run ESS and R code on a remote server and
output graphics on my local mointor.

What I tried:
I followed the manual at item 5.4.1 here:
http://www.gnu.org/software/emacs/manual/html_node/tramp/Remote-processes.html
. I failed with the error described here:
http://stackoverflow.com/questions/30043608/unable-to-start-device-x11cairo-in-r-on-mac-10-10.
I also tried and get this method working:
http://www.r-bloggers.com/run-a-remote-r-session-in-emacs-emacs-ess-r-ssh.
However, it still involves multiple steps.

Alternatively, I can manually modify the ssh connection method in
tramp-methods of the tramp.el file. But since it is a common issue to many,
I want to ask for a simpler/common solution.

Thanks
Vang