NB: I did not find a tutorial simple and understandable ...
Video is coming if you want.
Download 1 software: FileZilla
Download FTPVita.
Download the tutorial file: http://www.mediafire.com/download.php?63a0t6xc47bykv0 (I have changed it)
For exemple, I install the plugin: CWCheats.
(The 3 Famous plug-in for cheat for PSVita TN-C here: viewtopic.php?f=56&t=25415#p222384)
1) Start Filezilla
2) After installing FTPVITA on your PSVita (if it is not displayed, retransferred it under the name LOL.ZIP, to me its done), Start, it will show you an address. Example: ftp://192.168.1.31/
3) On FileZilla, Host is the *exemple* ftp://192.168.1.31/, click on Quick Connection (connection rapide)
4) Drag the folder SEPLUGINS (of .rar file tutorial), in the window down-right of the window's filezilla, wait for the copy to finish.
5) Ever on FileZilla, Back to the First Parent Directory, Go to : PSP > SAVEDATA > *SAVEDATAEXPLOIT* >
6) Drag the file GAME.TXT (of .rar file tutorial) on the savedata exploit. (Exemple: PSP/SAVEDATA/NPEH726118/GAME.TXT HERE)
7) Press [] on your vita, start game and press select 5 seconds.
Normaly its done

AFTER...
In the GAME.TXT :
ms0:/SEPLUGINS/CWCHEAT.PRX 1
Posibility:
ms0:/SEPLUGINS/CWCHEAT.PRX 1
ms0:/SEPLUGINS/NITEPR.PRX 0
or
ms0:/SEPLUGINS/CWCHEAT.PRX 0
ms0:/SEPLUGINS/NITEPR.PRX 1
0 = OFF
1 = ON
I see my SAVEDATA crash (error code) if you toggle two plugin but:
TempAR / CWCheat: Compactible *TESTED*