In Windows Live you can export and import contacts to do this, simply press ALT + C (to bring up the contacts menu), then simply click on "Save instant messaging contacts..."
You can also import them into your new one by going to the contacts menu, but instead click on "Import instant messaging contacts..." instead.
But before you do this, any contacts you wish not to include in your new one simply delete them before doing so, otherwise you will end up adding them to your new one.
Also once you have done so, if you no longer wish to use your old one then you can close the old account by visiting the link below to remove it (also note this will also delete the email address as well.)
http://windowslivehelp.com/solution.aspx?solution...-ae2c-91e158a4cc76
