Of course if you’re burning something like a BluRay disc then it can take quite a while. The time it takes to burn depends on how fast the drive is and how large the ISO image is, but it shouldn’t take too long to finish.
Simple right? That’s really all it takes. Click ‘Burn’ and wait until the image has finished burning to the disc.Insert a Blank Disk (CD or DVD, use the appropriate disk as necessary depending on the ISO file size).Navigate to the ISO image file that you want burned and click “OK”.Pull down the File menu and select ‘Open Disk Image’.Open the “Disk Utility” app, it’s located in /Applications/Utilities/.This process will be the same on virtually all versions of OS X: You’ll also need a disc and a SuperDrive, but that should be fairly obvious if you’re looking to burn a disk image of any sort to physical media. That isn’t necessary though, so as long as you know where the ISO image file is stored you can proceed as usual. Well, disable it, restart your MacOS, do the changes and then don't forget to enable it again.Before proceeding, it may be helpful to place the ISO image somewhere easy to find so that you can access it quickly with the Disk Utility app, the ~/Desktop/ is often a good place for that. basically, you need to restart your mac in recovery mode, go to menu utilities and open terminal, type crsutil status to check if it is enabled or disabled, then you can use csrutil disable or csrutil enable. Obs.: if your MacOS complain, you need to disable the CSR before change this. That's it, now when you open the Bootcamp assistant you can use the option that allows you to create a USB install boot disk. it will ask if you want to replace it, then you answer yes. Save this file, go back to the contents of the Boot Camp Assistant and drag the newly edited file into.
In my case I changed from Macbook7,2 to MacBookPro8,2.
If it is like PreUSBBootSupportedModels, change the name to USBBootSupportedModels, expand this line and at the item0, edit and write down your MacBook model as a string value. Open this ist file with a plist file editor or xcode, then look for a line saying "USBBootSupportedModels". Then find the file ist and drag and drop to a whatever folder you created before. go to your application>utilities, select the Boot Camp Assistant app, right click > show packages content.
So, for those who can't create the USB install disk, here some tip.