How to customize my own PfSense GUI?

ASGH

I would like to customize my PfSense version. I mean changing the Logo to be my own one, adding & translating some statements in the GUI.
Could you please guide me from where should I start, which version do I need to do that? Is it the full source code? Or regular ISO/Memory stick version?
What tool(s) do I need ?

Your advice would be appreciated.

ptt

http://forum.pfsense.org/index.php/topic,53210.0.html

http://doc.pfsense.org/index.php/Can_I_sell_pfSense

http://devwiki.pfsense.org/PfSenseDevHome/

ASGH

Appreciate your useful links.

I have read this page.
http://devwiki.pfsense.org/ReBrandingSupport

It says I need to change some files that are located in:
/etc/inc/globals.inc
/usr/local/www/javascript/sajax.js
/usr/local/www/wizards/*
/etc/motd
/etc/rc (ascii art: you may wish to add your own ascii art file to /etc/ascii-art/your-file.txt)
/tools/installer/conf/pfSense.lua (if you want the installer to display your product name)
i386 boot files (boot loader, etc)

I am planning to edit nono PfSense, my question (which should be simple!) how can I reach those files and then save my changes to be used as a nano version (for CF storage)?

Should I use software like PowerISO to edit directly the file pfSense-2.0.2-RELEASE-512mb-i386-nanobsd-20121207-1630.img? and then reach all intended file?
Just I want to know how to start this point.