Check the FAQ
. Both answers are in there. And by the way, making a second account is against the rules.
(The formatting looks better in the FAQ)
Can I change my user name?
The forum software does not let you change your user name.
If you mistyped your user name while registering, typed a user name longer than 15 characters that was then truncated, or mistakenly tried to put your email address in the user name field, promptly ask for it to be corrected using the Contact form.
If you are simply tired of your user name, consider the following problems that can result if your user name is changed:
Other forum members will be confused, wondering where you went or how an apparently new member appeared.
Your new user name will be shown next to each of your posts, but posts that mention you by name will still show your old user name, causing further confusion.
In particular, posts that quote your posts will say Originally Posted by (oldusername) while the linked-to post will not match that name.
If you have participated in editing any of the MacRumors Guides, the edit history will show the wrong information, listing the old user name as page author and in edit histories.
If you use the Marketplace forum, your records of successful transactions will probably be missed by other users.
If you use the same name at multiple websites and think that your user name at MacRumors should match, remember that making yourself easier to find across websites can have disadvantages as well. Using different user names adds to your privacy.
If you have been mentioned in lists or forum announcements or been given kudos for achievements, e.g., contest winners, member directories, top poster reports, or credit for news story submissions, they will reflect the wrong user name.
User names can be changed only manually by the administrators. While we understand that it is sometimes necessary, handling such requests, including the required recordkeeping, takes time away from work that benefits all forum users.
If you think that your case represents an exception to these cautions, use the Contact form to request a change of user name and explain the circumstances. You must mention that you have read this FAQ section; otherwise we will refer you to it. We will consider your request and grant it, deny it, or ask for more information.
We have found that this policy strikes the right balance between members with user name concerns and the forum community as a whole.
We prohibit user name changes made for the purpose of "hiding" from previously made posts, covering up a bad reputation, or to trick other users. You may not change user names by re-registering since re-registration violates forum rules.
The quality of your posts defines you more than your user name, but once you've established a presence in the forums people tend to recognize you by your user name and your avatar if you have one. It benefits the community for you to keep your user name, which is why we discourage user name changes. If you are itching for a change and have an avatar, we suggest that you upload a new avatar!
How do I cancel my account?
For additional privacy, you are welcome to remove the information in your User Profile (Instant Messaging names, Location, etc.) since this information is visible to the public for both active and inactive MacRumors accounts.
If you have subscribed to any forums or threads, have asked for email notifications, and are no longer interested in receiving those messages, delete the subscriptions on your List Subscriptions page.
If there are exceptional circumstances, such as an employment contract, that require that your account be canceled to prevent you from logging in, use the Contact Form to let us know. We'll probably direct you to this FAQ section unless you tell us you've already read it!
Canceling an account does not remove previously made posts from the forums, nor quotes of those posts by other members. If you are concerned about information in one of your previous posts (e.g., it contains too much personal information), you can edit the post yourself or report it to the moderators and ask that it be deleted. We strongly discourage you from editing or deleting large numbers of previous posts, since that may leave thread discussions "broken" or confusing to those who read them in the future.