Head on over to to the site using this handy text, log in with your GW2 credentials, and the rest should be self-explanatory (if it doesn't immediately take you to the linking process, there's an option on the left to do so). 

Well it turns out I was automatically linked to an account...but not the account I wanted to be linked to. Rather than been linked to the launch day GW1 account I had I'm linked to one I bought in a steam sale less than 6 months ago...great.

EDIT: That picture is pretty awesome though.

Congratulations! You have successfully linked your Guild Wars and Guild Wars 2 accounts. In doing so, you now have access to the exciting rewards awaiting you inside the Hall of Monuments. The following Guild Wars 2 account information will now be used to log in to both Guild Wars and Guild Wars 2:

:D

Uh ... I linked my account when I first created it. This is new?

@DeeGee: Some people may have used a different email address than their original account. I guess this means they can now link them.

@Dark_Lord_Spam: Now that's a Quaggan I can get behind.

IT is done managed to get 6 points in mine without really trying it's good enough for all of the HOM Heritage armor which is all I really cared about in the first place. Worst thing they do is throw it all up on the Gem shop in a year or so.

Sweet!

Also I didn't notice this before if it was available, but apparently you can change your Account Name on the "Edit Profile" page. That's convenient.

@Dark_Lord_Spam: Now that's a Quaggan I can get behind.