Call of Duty MW3 PS3 elite map packs transfering
Solution 1:
It sounds like you're asking if it's possible to just load the content from a subaccountt to the main account.
No, you can't do that unfortunately. The master account holds the power so if you're looking to reinstall content to the master account, the player must be logged in to the master account.
You may need to reset the password on the master account.
You can reset your PlayStation Network password and gain access to any DLC purchased and associated with that account. You'll need to at least remember the email account used to create the account to reset the password.
Sony has detailed these steps for you:
To use this feature, you may be required to update the system software.
You can use the following method to reset your password if you forget it.
Select (PlayStation™Network) > (Sign In).
Select [Forgot your password?] from the sign-in ID (e-mail address) and password screen.
Enter your sign-in ID (e-mail address) and birth date
Reset your password using a PC. An e-mail message is delivered to the address that you used as your sign-in ID. Follow the steps in the e-mail message to reset your password using a PC.