Okay I have created a sub account on my ps3 as a new user. I wanted to change my psn online id. So I have copied all game data from the old account to my new account, but when I go to play the game it still says the trophies and data belong to the old account. I don't want to delete the old one and lose all my saved games and trophies, is there a way to either unlock and allow my new user to own the data and trophies or transfer the trophies and data so that my new account may own it?
At present, there is no way to transfer trophy information from one account to another (still). Logically, it doesn't make sense for trophies to be transferable. This person earned this proof that they did something - what meaning would these have if you could transfer them to someone else? This would certainly allow for a shim to act as a psn id change, but that would be the wrong solution to the problem.
Some few saves and other data can be copied over but often, like trophies, these are usually non-transferable as well. To determine which data can be transferred, you would have to go through each and try it. The logic behind this is probably the same as trophies and possibly even related to how much easier it is to cheat trophies with someone else's saves.
You still cannot change your psn id and there are no practical workarounds. All you can do is start over. Sony might have reasons, but it is a hotly discussed feature that exists on the Japanese PSN. There has never been an outright denial of the future possibility (only statements that implementing this feature is "very technically complex").
On PS4 you can sort of get around this by changing your real name, but that doesn't allow numbers or special characters and will not help you on PS3.