townsbg wrote: I am not a linux person so how do I install it?
You go to Google, type install qemu fedora then press Enter and the top hit will probably be, How to use qemu - FedoraProject.
The qemu-img command is what you use to convert the image and there are plenty of examples already on the Internet, as well Wil also already posted one in this thread, and a further search of Google will yield even more. Once installed then in a Terminal you should be able to type man qemu-img for its man page.