@Coding Badly Thanx for the tips 
• pinMode is always first. digitalWrite is always second. digitalRead is always third. millis or delay is always fourth. With those four functions you have the ability to perform crude debugging. If possible, Serial is next.
So it should basically be just re assigning of pins right? (I know you might not be able to answer unless you go through the datasheet properly)
My question is where do I edit these parameters from? (Sorry if I am being naive about it)
Finally I may not actually port it because I think people have already ported it here.
(Did anybody on this forum did the above porting?)
I just wanted to know what were the basic things you do for such a porting.
You may want to spend some time with Google performing general searches. For example, this looks helpful...
http://blog.omegacs.net/2010/06/26/getting-started-with-xmega-differences-from-atmega-part-1/
Yes. That was the link that first got me interested in the chip.
I believe the Arduino IDE ships with a compiler for the XMega processors.
Shouldnt the compilers be the same?