PSVita должна быть на прошивке 3.65, 3.67 или 3.68 (другое п.о. не поддерживается). Если вы используете более старую прошивку, то тщательно решайте на какую версию программного обеспечения вам обновиться, затем найдите надежное руководство по PSV-хаку. Помните, что на прошивке 3.65 у вас есть возможность установить "Enso" (супер хак), тогда как на 3.67 и 3.68 вы этого не сделаете.
Для установки на PSVita OLED модели понадобится карта памяти.
Для установки на PSVita Slim модели или PSV TV карта памяти не нужна, поскольку эти модели имеют внутреннее хранилище. Убедитесь, что у вас есть как минимум 270 МБ свободного места.
Ваша PSVita должна быть связана с любой учетной записью PSN (при этом ее не нужно активировать).

Note that the following guide is for advanced users and a bit more complicated than the previous hack that only required you to visit a website. If you don't understand the guide below or how to use these tools, you should neither file an issue here nor annoy me on twitter, but rather seek help on /r/vitahacks (check for duplicated questions first!) or wait for an easy installer by somebody else.

Download h-encore and extract it on your computer.

Download and install qcma, psvimgtools and pkg2zip (check the releases section for the binaries).
If you don't know where to put psvimgtools and pkg2zip binaries, just put them in the h-encore folder.

Download the vulnerable DRM-free demo of bitter smile (yes, that's the user entry point).

Extract the demo using this command in terminal/cmd:

pkg2zip -x PATH_OF_PKG

This will output the files to app/PCSG90096.

Copy the contents of the output app/PCSG90096 to the folder h-encore/app/ux0_temp_game_PCSG90096_app_PCSG90096 (such that the files eboot.bin and VITA_PATH.TXT are within the same folder).

Copy the license file app/PCSG90096/sce_sys/package/temp.bin to the folder
h-encore/license/ux0_temp_game_PCSG90096_license_app_PCSG90096 and rename the just pasted file temp.bin to 6488b73b912a753a492e2714e9b38bc7.rif. Be careful with the file extension, it should not be .rif.bin. Again, this file should be in the same folder as VITA_PATH.TXT.

Start qcma and within the qcma settings set the option Use this version for updates to FW 0.00 (Always up-to-date) to spoof the System Software check.

Launch Content Manager on your PS Vita and connect it to your computer, where you then need to select PC -> PS Vita System, and after that you select Applications. If you see an error message about System Software, you should simply reboot your device to solve it (if this doesn't solve, then put your device into airplane mode and reboot). This should create a folder at PS Vita/APP/xxxxxxxxxxxxxxxx on your computer (see qcma settings where this folder is), where the folder xxxxxxxxxxxxxxxx represents the AID (account ID that is 16 characters long) that you need to insert here. If the AID is valid, it will yield a key that you can now use to encrypt the demo.

Change directory to the h-encore folder in terminal/cmd and use the key to encrypt all folders using (make sure you don't confuse the key with the AID, the key is 64 characters long!):

psvimg-create -n app -K YOUR_KEY app PCSG90096/app
psvimg-create -n appmeta -K YOUR_KEY appmeta PCSG90096/appmeta
psvimg-create -n license -K YOUR_KEY license PCSG90096/license
psvimg-create -n savedata -K YOUR_KEY savedata PCSG90096/savedata

The folder h-encore/PCSG90096 should then contain sce_sys and all 4 folders from above, and within these folders you should find files called X.psvimg and X.psvmd, where X has the same name as the folder. Backup this folder, since if everything has been done correctly, you don't need to redo all the steps to install it onto another device with the same PSN account.

Copy the folder h-encore/PCSG90096 to PS Vita/APP/xxxxxxxxxxxxxxxx/PCSG90096 and refresh the database under qcma settings.

The h-encore bubble with a size of around 243 MB should now appear in the Content Manager and that's what you finally need to transfer to your PS Vita. If the size does not match or you get the error C2-12858-4, then it's because you did not do it correctly! Please re-read the instructions more carefully then. If you get the error You can only copy applications that your account is the owner of, then it's because you have used an AID that is not of your account, go back to step 8.

Launch h-encore to exploit your device (if a message about trophies appears, simply click yes). The screen should first flash white, then purple, and finally open a menu called h-encore bootstrap menu where you can download VitaShell and install HENkaku. If it prompts the error Cannot start this application. C0-11136-2, then it's because you did not do step 6. correctly.

Enjoy. Note that you have to relaunch the exploit everytime you reboot or shutdown your device. Of course if you only put your device into standby mode, you don't need to relaunch.