Help with xbox live gamer tag and renewing it?

I dislike my gamertag and want to change it. i was wondering, if i put a new live card on and renew it, will it let me change it? also if i do change it does that mean i loose ALL of my achievment and levels on call of duty and other games? also try to suggest some new gamertags please. nothin to do with sports though, maybe with like somethin italian in it|||If you re-new your XBL membership, MS will NOT let you change your gamertag for free. You will have to pay 800 MS points [$10] to change your gamertag. If you change your gamertag, you will NOT lose any of your achievements, etc.|||You can change it at any time but i think it's like 8 dollars (or the equivalent in MS points) you don't lose all your achievements or anything like that. Just go to manage account and you can change it from there.