Have a read of these threads...
Adjust CO -
http://www.xt660.com/showthread.php?t=55
Adjust TPS -
http://www.xt660.com/showthread.php?t=56
Removing Snorkel -
http://www.xt660.com/showthread.php?t=12547
If you've got a K&N, then I'd leave it for now.
Fit the DNA stage 2 when you have the ability to adjust the fuelling (ie: fit a Kev Mod).