Create a New Email Address
Your email address can only be tied to one PSN account so, in order to create a new PSN ID, you need to create a new email address. The PlayStation Network does not care what type of email account you use, but the email account will be used to recover your account information, so you must be able to access it. Navigate to a website like Google Mail, Yahoo! Mail or Hotmail and follow the instructions to create your new email address before proceeding.
Create a New User
Since you can only create one PSN ID for each account on your PS3 system, in order to create a new PSN ID, you must first create a new account. Scroll over to the "Users" section of the PS3's XMB and select the "Create New User" option. Type a name for the new user in the space provided and select the "OK" option to create the new user.
Create a New Account
Once you have created the new user account, you can create the new PSN ID. Scroll over to the "Users" section of the XMB and select the new user account to sign in using that account. Scroll over to the "PlayStation Network" section of the XMB and select the "Sign Up for PlayStation Network" option. Select the "Create a New Account (New Users)" option and fill in the required information to create your PlayStation Network account. When prompted, enter the new PSN ID that you want to use and finish the account creation process.
Sign Into the New Account
Once you have created your new PSN account, you must sign in to use the new PSN ID. Scroll over to the "PlayStation Network" section of the XMB and select the "Sign In" option. Enter your new PSN account password in the space provided and select the "Sign In" option to sign into the new account.