Through the power of homebrew.
Just takes a simple email, read via the PSV email app of which is preinstalled on each device.
http://hackinformer.com/2015/09/24/mr-gas-releases-methode-to-write-to-the-vita-filesystem-pstv-whitelist-patch/
--------------------------------------------------------------------------
1. Download this file:
https://www.dropbox.com/s/ms6kx2b3xjx8l1g/writer.eml?dl=0
--------------------------------------------------------------------------
2. Open that file with a compatible email client (such as thunderbird), and forward it to your email account registered on the vita's email app.
--------------------------------------------------------------------------
3. Load the vita email app. Locate your email and load it. You should see something like this:
Click on the attached image. You will now get this:
DO NOT CLICK OK. Instead, hold the PS button and quit the app.
--------------------------------------------------------------------------
4. Go back into the vita email app. The settings have now been cleared, so log back into your email. The client is now hacked.
--------------------------------------------------------------------------
5. Download
https://www.dropbox.com/s/d6gef9cx07n7kx6/list_launch_vita.dat?dl=0 and rename it to
#0 - make sure there is NO file extension. Enable file extension editing in windows if you havent done so already.
--------------------------------------------------------------------------
6. Email it to your vita's registered email address with the title of
ur0:game/launch/list_launch_vita.dat
--------------------------------------------------------------------------
7. open it like before. quit the app.