Go to you tube and search for Lockscreen 3D Cube. You have to download ifile from Cydia in order to replace the pictures. You can use pictures from your cameral roll. Once you get into ifile, the cube is located under var/stash/themes/then the name of your theme, like lockscreen 3D Cube or 3D cube and background changer. Then jus go into images. Copy your own pictures from your camera roll, located at var/mobile/media/DCIM. Iy ou look at the video it helps, but the vieo is from another cube theme and he got his pictures from a different location, but it's still the same concept. Let me know if any of this doesn't male sense.