An useful article from Gamefaqs I would like to share here.
Several times a week I see these questions so figured I would repost the guide so those of you interested can be informed. Go get the Soul Sacrifice demo!
Why would you want to have the ability to use multiple accounts on your Vita? Its a great way to enjoy different regions, such as demos, PSN downloads (so you dont have to pay import fees). I can think of three reasons to have this ability:
1. HK account (since its in english) to get Demos and DLC for games only released in Asia. This is why I did it as I wanted to demo Ragnarok Odyssey before I decided to preorder it.
2. People who want multiple same region accounts. Some people want an acct for casual play and one for only games they plat. Some want an online profile and an offline.
3. Family members or friends who want to share the same system, yet have different accounts.
Couple of points before you start. First, ALWAYS back up your memory card data (downloads, saves, etc) to your PC/MAC/PS3 before your try just in case there is an issue. Second, when you do this, expect to easily swap out accounts, and mem cards tied to those accounts, in less than 5 mins but it does reformat your Vita. IE your icons and wallpapers will be reset. Also, please sync your trophies to PSN. Lastly, there has been some worry about affecting welcome park activities, but this is untested.
Here are the step by step instructions, and in the description I am assuming you are going from a NA acct to an HK acct, but any combo of the above would work:
1. Power off Vita
2. Remove your memory cards and game cartridges that are assigned to your NA account.
3. Power on VIta, go to settings, reformat, reformat Vita.
4. This will reformat the Vita!
5. ****MAKE SURE YOU DEACTIVATE THE DEVICE THAT IS ASSIGNED TO YOUR NA ACCOUNT!!!****
6. The system will reboot and look like the second you opened from the box.
7. Go through the setup functions, select YES on use of existing account. Enter your HK account information.
8. Activate the VIta to the HK account.
9. Insert memory card #2 with your HK information and play!!!You can do this as many times as you want, with no issues, as long as you DEACTIVATE (step 5) each time. The whole process takes less than 5 minutes.
If you do not have a HK account, please go here to get one:
http://asia.playstation.com/hk/en
Here is a youtube video link of what I went over, please review before you try:
http://www.youtube.com/watch?v=0DWsKE6tStQ
Anyone else, please feel free to add or correct me. Please request sticky!
Credit to: yankee6903@gamefaqs
Direct link to original post: http://www.gamefaqs.com/boards/620272-playstation-vita/65626763
P.S. Unfortunately, the thread is closed and will soon be pruned by the system. There’s no direct way to save or bookmark it. You can save this post for future reference.