I do not know if it works for i62HD, I guess yes.
The folder is "\usr\share\system_manager\images". You must use file manager other than one of Onyx or in PC. I use OTFM.
And there might be more than 10 pictures for screensaver. Just go on screen_saver10.png, screen_saver11.png, etc. I have about 20+ of them.
It is also possible to copy pictures to firmware zip file (on PC) and then make firmware update. In that case you wil not need OTFM file manager.