Frustrating 360 problem

[Experiment626]

Got a 360 about a month ago and have played around 5 games to death, got loads of achievements etc...tonight I decided to signup to XBOX live but my offline username was taken so made a new one, assuming that all my in game achievements and so on would be moved over to the Live Gamertag...not the case, now I have my Live ID and my offline ID...the latter having all my achievements and frankly, i don't want to have to do it all again, anyway of moving them over to my Live tag?

 

[Experiment626]

already paid my £4.99 didn't i

Just never occured to me to change the offline tag first before signing up...doh

 

[Experiment626]

I've tried renaming the offline one to my online one but it won't allow me to because the online one already exists on the hard drive...can't find a function to delete the online profile anywhere?