Download the software " Live usb install" from this link for a deb distribution package: http://live.learnfree.eu/download/
After that realize the instalation by the default command dpkg -i <packet name>.deb
After instalation execute the software and set IMG write on mode option:
In Install from set im IMG File your file.iso that you was download to create a image
In install to set the device usb that you want to save the image, maybe do not appear the device, please, set the botton in right side to refresh the devices.
And after click in OK to start the procedure to create the image.
After that just do the test: