How do you create a sub account for the Playstation Network When you already have a master account

How do you create a sub account for the Playstation Network When you already have a master account?
okay so im on the computer right now and i already have a master account, i want to make another sub account but wen i go to the us.playstation.com homepage where it says sign up, how can i make a sub account instead of making a new master account, which i need to make in the first place?
PlayStation - 1 Answers

Random Answers, Critics, Comments, Opinions :
1
Go to sign up on the Playstation homepage, after it tells you that you need to use your master account to create a sub account, press continue and it will get you to sign in with your master account, so then you can create a sub account.